an image for the logo
 
Local forecast by
"City, St"
Current Hazards Watches/Warnings
Hazardous Outlook
National Outlooks
Hurricane Center
Emergency Mgmt.

Current Conditions Observations
Rivers/Lakes AHPS
Satellite Imagery
Storm Reports

Radar Imagery Wilmington Radar
Nationwide

Forecasts
Discussion
Activity Planner
Hourly Weather
    Graphs

Local Forecasts
Fire Weather
Graphical
Hydrology
   -Drought Monitoring
Marine
Marine Portal
Model Guidance
Surf Zone
-Rip Currents
Space
Text Products
Tropical
Tsunami

Climate
Climate Plots
Local
National
CoCoRaHS
More...

Weather Safety
Storm Ready
SkywarnTM
Preparedness
Safe Boating Tips
Weather Radio

Miscellaneous
Significant Events
News Archive
NOAA in the
    Carolinas

Science/Technology
Weather Calculator

Other Information
EEO/Diversity
Outreach/Education
Product Guide
Virtual Tour


Contact Us
E-mail Webmaster
Web Site Survey

FirstGov.gov is the U.S. government's official web portal to all federal, state and local government Web 
resources and services.
Wilmington NC Science and Technology
Welcome to the Wilmington North Carolina National Weather Service science and technology page. On this page you will find comprehensive explanations of local and regional weather phenomena that make forecasting for the area a challenge. Use the quick links below to navigate to the section you are interested in.
Sea Breeze
The sea breeze probably is the most influential local weather phenomena in our area. The sea breeze develops as land heats up...air rises and is replaced by cooler air that has been over the water. See graphic...

The sea breeze can have a dramatic affect on temperatures along and sometimes well inland of the immediate coast. The sea breeze can also act as a "trigger" for thunderstorms.

Forecasters at The National Weather Service in Wilmington have classified several types of sea breezes through the years. Click on the images below to get a closer look at the radar and satellite configurations. Many of the loops will be posted as they become available.
a picture of the beginning of a classic sea breeze
The classic sea breeze occurs when a weak pressure gradient is present. The shape closely resembles the coast. There is always an inflection point with the classic sea breeze. It is often accompanied by weak showers and thunderstorms. The classic sea breeze can propogate well inland.
Classic Sea Breeze
The Southerly Resultant Sea Breeze with Inflection is one of the most common types of seabreezes in our area due to the prevailing flow. This feature always has an inflection point which is displaced to the north or northeast. It generally stays confined to the coastal counties and can be accompanied by weak pulse storms.
a picture of the beginning of a southwest resultant sea breeze
Southerly Resultant Sea Breeze With Inflection
The Southerly Resultant Segmented Sea Breeze partially mimics the coastline but stays close to the coast across the southern areas. There is no inflection point. This sea breeze often has little in the way of convection because the atmosphere is capped.
a picture of the beginning of a southwest resultant sea breeze
Southerly Resultant Segmented Sea Breeze
The Southerly Resultant Hybrid Sea Breeze remains confined to the coast across the northern and southern areas while moving inland toward the center.
a picture of the beginning of a southwest resultant sea breeze
Southerly Resultant Hybrid
The Northeast Resultant Sea Breeze with Inflection slightly mimics the coast. This feature always has an inflection point that is displaced to the west. The inland propogation is limited...and with the prevailing Northeasterly flow...convection is usually limited because of poor instability.
a picture of the beginning of a southwest resultant sea breeze
Northeast Resultant Sea Breeze with Inflection
The Northeast Resultant Segmented Seabreeze partially mimics the coast and remains confined near the coast along the northernmost segments. This feature does not have an inflection point and usually inland propagation is limited.
a picture of the beginning of a southwest resultant sea breeze
Northeast Resultant Segmented Sea Breeze
Sea Fog
am image of a ship in sea fog
Sea fogs are advection fogs that form in warm moist air cooled to saturation as it moves over colder water. The colder water may occur as a well-defined current, or as gradual latitudinal cooling. The dewpoint and the temperature undergo a gradual change as the air mass moves over colder and colder water. The surface air temperature falls steadily, and tends to approach the water temperature. The dewpoint also tends to approach the water temperature, but at a slower rate. If the dewpoint of the air mass is initially higher than the coldest water to be crossed,
and if the cooling process continues sufficiently long, the temperature of the air ultimately falls to the dewpoint, and fog results. However, if the initial dewpoint is less than the coldest water temperature, the formation of fog is unlikely. Generally, in northward moving air masses or in air masses that have previously traversed a warm ocean current, the dewpoint of the air is initially higher than the cold water temperature to the north, and fog will form, provided sufficient fetch occurs. The rate of temperature decrease is largely dependent on the speed at which the air mass moves across the sea surface, which, in turn, is dependent both on the spacing of the isotherms and the velocity of the air normal to them. The dissipation of sea fog requires a change in air mass (a cold front). A movement of sea fog to a warmer land area leads to rapid dissipation. Upon heating, the fog first lifts, forming a stratus deck; then, with further heating, this cloud deck breaks up into a stratocumulus layer, and eventually into convective type clouds or evaporates entirely. An increase in wind velocity can lift sea fog, forming a stratus deck, especially if the air/sea temperature differential is small. Over very cold water, dense sea fog may persist even with high winds.
Waterspouts
Fair-weather waterspouts are small tornado-look circulations extending from the ocean surface up into a towering cumulus or cumulonimbus cloud. Fair-weather waterspouts occasionally occur during the warm season across North and South Carolina coastal waters and are a hazard to boaters and beachgoers. Wind speeds in large waterspouts can rival that of small tornadoes and sometimes reach over 100 mph. Fair-weather waterspouts can sometimes move onshore as a tornado, but normally weaken and dissipate within a minute of reaching shore due to increased surface friction and turbulence.

Tornadic waterspouts (those associated with a severe thunderstorm) are formed through classic tornado processes involving extreme wind shear and a strong parent mesocyclone. Fair-weather waterspouts are a separate entity. As a result, tornadic waterspouts are not considered in this forecasting scheme.

The Waterspout Risk forecasting scheme cannot forecast the occurrence of an individual fair-weather waterspout. Due to their small size and transitory nature, even advanced Doppler weather radar is of little use in this regard. We count on real-time reports from mariners and spotters on the beach to alert us to the actual development of waterspouts. The purpose of this waterspout risk scheme is to forecast the broad atmospheric conditions that are favorable for the eventual formation of fair-weather waterspouts. This is intended to heighten public awareness on days when waterspout formation is likely and prevent a waterspout from "sneaking up" on an unsuspecting mariner or beach-goer.

Generally speaking fair weather waterspouts form in environments characterized by little to no vertical wind shear below 6000 feet in altitude, deep moisture, good instability (as measured by CAPE) and moderate to steep low-level lapse rates. The forecasting scheme weights each of these factors and arrives at a numerical and categorical forecast characterizing the risk of waterspout occurrence for the day.

Research at other offices and qualitative observations locally seem to indicate that waterspouts form preferentially in the vicinity of morning land-breeze boundaries. This seems logical given the boundary will naturally be a focus for converging air at the lowest levels. Helicity on the sub-mesoscale will also be enhanced in these areas. Additional research may attempt to factor in the probability of land-breeze formation and its effect on waterspout probability.

Shown below is an image of the Waterspout Calculator forecasters use to input meteorological data to derive the waterspout risk. Click on the links below to see the specific description of the parameters.
am image of the waterspout risk calculator
CLOSE WINDOW

First, CAPE is observed over the entire sounding. Zero CAPE gives no correlation...up to 1200 J/kg gives moderate correlation and 1200 to 2000 J/kg gives a high correlation.

The distribution of instability is alos important. Waterspouts require instability to be present in the lower portion of the troposphere where convective vertical velocities can be wrapped into a waterspout's circulation. This is measured by comparing temperatures at 900mb and 600mb. The greater the difference in these temperatures indicates a larger amount of potential instability. This is true to a point...however very steep lapse rates nearing dry adibatic in the layer can occur when the atmosphere is too dry to support convection or waterspouts.

Up to 17.5 degrees C difference...no correlation
17.5 to 18 degrees C or greater than 20 degrees C...moderate correlation
18 to 20 degrees C...high correlation
CLOSE WINDOW

Analyze the winds in the sounding at the 1000...2000...4000 and 6000 foot agl layers. Shear between each of these layers can be computed by doing a vector subtraction of the u and v components of the winds at each level. The resultant wind...i.e. the shear...is an indication of how much distortion a rising updraft and growing cumulus cloud will enconter as it ascends. Waterspouts...despite their occasionally extreme wind speeds...are very fragile and can be disrupted by high values of wind shear.

The following chart shows values of wind shear which have been found to be correlated with waterspout formation:

No Correlation   Moderatre Correlation   High Correlation
1k-2k ft Vector Shear...        >6kt         4 to 6kt     <4kt
2k-4k ft Vector Shear...        >6kt         4 to 6kt     <4kt
4k-6k fr Vector Shear...        >5kt         3 to 5kt     <3kt
CLOSE WINDOW

Since waterspouts are tied so closely to moist convective processes, the presence of sufficient moisture in the atmosphere is obviously important. Analysis of three years of soundings on days with waterspouts has revealed moist air(characterized by dewpoint depressions < 5 C) should extend from the surface up to 600mb.

First dry layer(<5C)layer
Below 750mb...no correlation
750mb to 600mb...moderate correlation
Not present or present above 600mb...high correlation
Rip Currents
am image of the rip current risk calculator
Rip currents are powerful, channeled currents of water flowing away from shore. They typically extend from the shoreline, through the surf zone, and past the line of breaking waves. Rip currents can occur at any beach with breaking waves, including the Great Lakes.

A daily rip current outlook is included in the
Surf Zone Forecast which is issued by many National Weather Service offices...including Wilmington North Carolina. A three-tiered structure of low, moderate, high is used to describe the rip current risk. This outlook is communicated to lifeguards, emergency management, media and the general public.

Just like the Waterspout Risk Calculator...there are several components that go into derivine the rip current risk. Click on the links to the right of the image below to read a description of the component.
CLOSE WINDOW

Wind direction is very important to the development of strong rip currents. With the orientation of our beaches in this area...a subtle change in wind direction can have significant impacts on the development and intensity of rip currents.

For the Southeast facing beaches...like the ones in Pender...Horry...and Georgetown counties...a wind direction of 80 degrees to 170 degrees is important. For the beaches in New Hanover county...which face more to the east...a wind direction of 70 degrees to 160 degrees is important. For the Brunswick County beaches...which face more to the south...a wind direction of 150 degrees to 220 degrees is important.
CLOSE WINDOW

The swell component in the wave spectrum also plays a significant role in the development and intensity of rip currents. The longer period swells...like the ones that eminate from a distant hurricane... provide more power by pushing more water on to the beach. In general...the swell direction must be normal or perpindicular to the beach or county in question.
CLOSE WINDOW

Tides play a significant role in the development of rip currents. The gravitational influence of the earth's moon is stronger three days either side of a full or new moon. More weighing is given to the scheme during these periods.
Also studies have shown the frequency of rip currents is higher during low tide so more weighing is alos given if an extremely low tide occurs durng typical beach going hours.
CLOSE WINDOW

The synoptic flow plays a role in the development of significant rip currents. Once again the direction is important for the respective beaches...with the southeast facing beaches favoring the direction range of 80 and 170 degrees. The south facing beaches favoring the direction range of 150 amd 220 degrees with the east facing beaches favoring a direction range of 70 and 160 degrees.
The longevity of the flow is important as well. Not only does the direction have to be in the favored range...the flow must have occurred 80% of the time during the previous 48 hours.
Tropical Weather Forecasting
There are several good pages to view tropical weather forecasts and the various parameters that go into them. In the following sections...a brief description will be given of the field...followed by a link to the page. This section is designed to be a collection of the pages as well as a brief introduction and explanation of the parameter. A more rigorous explanation is generally available on each page.
Model Guidance...Track and Intensity
Saharan Air Layer Analysis
African dust is generally thought to be an inhibiting factor for the development of tropcial systems in the Atlantic. It is associated with very dry air at the mid levels of the atmosphere. Tropical systems develop and intensify in areas where the moisture content is high. The Saharan Air can be analyzed at The Cooperative Institute for Meteorological Satellite Studies...CIMMS.
Sea Surface Temperatures/Tropical Cyclone Heat Potantial
Warm water is a necessary component to tropical storm development. Water temperatures of 80 degrees Fahrenheit or about 26.5 degrees Celsius are the thresholds. A good site to view water temperatures can be found at the Tropical Cyclone Heat Potential Page. The depth of the warm water...referred to as the heat potential...is also critical and can be examined at the same page.
Satellite Links
A coupel of excellent sites for viewing tropical regions include the NESDIS site and the Navy site.
Wind Shear
Basically...wind shear refers to any change in wind speed or direction along a straight line. In the case of hurricanes, wind shear is important primarily in the vertical direction--from the surface to the top of the troposphere. Wind shear of less than 10 knots is very condusive to tropical cyclone formation. Increasing values of wind shear are less condusive for rapid development and values exceeding 20 knots are usually destructive. Once again...there are a couple of excellent sites to view current and forecast wind shear. The first is CIMMS. The Penn State site is anothe good reference. You need to select the 850-200MB parameter on the GFS model and step through the six hour panels.
Jeff Masters of The Weather Underground has an excellent wind shear tutorial.
High Resolution 10m Wind
Sfc 2m Temp/10m Wind
Sfc 2m Dewpoint/10m Wind
SLP, 1000-500MB Thickness
925MB Moisture Transport
850MB Height, Temp, Wind
850MB Height, RH, Omega
850MB Moisture Transport
700MB Height, Temp, Wind
700MB Height, RH, Omega
700MB Moisture Transport
500MB Height, Temp, Wind
500MB Height, RH, Omega
500MB Height, Vorticity
300MB Wind Speed
250MB Wind Speed
Precipitable Water, SLP
CAPE, SLP, 10m Wind
Best CAPE, CIN
Best LI
1 Hour Pcpn
6 Hour Pcpn
12 Hour Pcpn
Composite Reflectivity
Freezing Level
Clouds
WRF Two Kilometer High Resolution Model
Projection
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Loop 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
10 meter wind
10 meter winds are the standard level surface winds are measured.
2 meter temp/ wind
2 meter temperature is the standard level surface temperatures are measured.
2 meter dewpoint
2 meter dewpoint is the standard level surface dewpoints are measured.
SLP/1000-500mb Thickness
This parameter is based on the difference in heights between 2 pressure levels. h=z1-z0 From the hypsometric equation one can theoretically derive the thickness base on a mean temperature for a layer. h=(R/g)*Tmean*ln(P0/P1) Where R = gas constant g = acceleration of gravity Tmean = mean temperature for the p0 to p1 layer. Since R and g are constants, then for any given layer the thickness is proportional to the mean temperature of the layer. Thus the cooler the layer the less thick the layer is. This parameter is used for determining the thermal structure of a front, delineation of rain, snow or freezing precipitation, and also the movement of an MCS.
925mb Moisture Transport
Moisture Transport is a derived parameter of the model wind field and the moisture field. The values displayed multiple the two fields. This field shows where moisture is advecting. These fields are best from 700 mb and lower.
850mb Height/Temp. Wind
850mb height is used determine low level thermal troughs and ridges. The 850mb level is a standard level used to assess fronts...low level jets. etc.
850mb Height/RH/Omega
Upper vertical motion is closely connected to the advection of vorticity in the upper troposphere and warm air advection in the lower troposphere. The Omega equation based on these advections can approximate the vertical motion in the atmosphere. The depiction of a negative omega indicates areas of upper vertical motion and positive omega represents downward vertical motion. Typically users have used the 700 mb level to diagnosis vertical motion on the synoptic scale but other levels are just as valuable such as 850 or 500 mb based on your elevation.
850mb Moisture Transport
Moisture Transport is a derived parameter of the model wind field and the moisture field. The values displayed multiple the two fields. This field shows where moisture is advecting. These fields are best from 700 mb and lower.
700mb Height/Temp/Wind
The 700mb level is a standard level in the atmosphere...approximately 9k feet above the surface. This level is used to analyze shortwave troughs and ridges.
700mb Height/RH/Omega
Upper vertical motion is closely connected to the advection of vorticity in the upper troposphere and warm air advection in the lower troposphere. The Omega equation based on these advections can approximate the vertical motion in the atmosphere. The depiction of a negative omega indicates areas of upper vertical motion and positive omega represents downward vertical motion. Typically users have used the 700 mb level to diagnosis vertical motion on the synoptic scale but other levels are just as valuable such as 850 or 500 mb based on your elevation.
700mb Moisture Transport
Moisture Transport is a derived parameter of the model wind field and the moisture field. The values displayed multiple the two fields. This field shows where moisture is advecting. These fields are best from 700 mb and lower.
500mb Height/Temp/Wind
Probably the most common used mid level standard level in the atmosphere... approximately 18k feet above the surface. This layer is used to analyze short and long wave troughs and ridges...jet streams.
500mb Height/RH/Omega
Upper vertical motion is closely connected to the advection of vorticity in the upper troposphere and warm air advection in the lower troposphere. The Omega equation based on these advections can approximate the vertical motion in the atmosphere. The depiction of a negative omega indicates areas of upper vertical motion and positive omega represents downward vertical motion. Typically users have used the 700 mb level to diagnosis vertical motion on the synoptic scale but other levels are just as valuable such as 850 or 500 mb based on your elevation.
500mb Height/Vorticity
In meteorology vorticity refers to the measure of rotation or spin of the atmosphere. This field when viewed on a constant pressure surface when assuming adiabatic flow can help determine upward and downward vertical motion on a synoptic scale. In an Eulerian framework, one where we can watch the change of vorticity at a fixed point one can sense whether the value of the vorticity is increasing or decreasing with time. If it is increasing then this is positive vorticity advection and one can infer upward vertical motion at this point. The opposite is true for negative vorticity advection. 500 mb level is used for this assumption as it is near the level of non divergence.
300mb Wind Speed
An important standard level in the atmosphere ranging from 30 to 35k feet...depending on the season. This field is used to analyze thermally direct and indirect circulations of ageostrophic circulaitons of jet streaks as well as long wave troughs and ridges.
250mb Wind Speed
An important standard level in the atmosphere ranging from 35 to 40k feet...depending on the season. This field is used to analyze thermally direct and indirect circulations of ageostrophic circulaitons of jet streaks as well as long wave troughs and ridges.
Precipitable Water/SLP
Precipitable Water, PW, is the total atmospheric water vapor contained in a vertical column extending between any two specified levels, generally from the ground to the top of the atmosphere or the top of an atmospheric model. PW is used to determine the abundance or lack of moisture. There are 3 factors which are needed for convection to form; these three factors are the availability of instability, upward vertical motion, and available moisture. PW is one way a meteorologist monitors the moisture in the atmosphere.
CAPE/SLP/10m Wind
is the amount of energy a parcel of air would have if lifted a certain distance vertically through the atmosphere. CAPE is effectively the positive buoyancy of an air parcel and is an indicator of atmospheric instability, which makes it valuable in predicting severe weather.
Best CAPE/CIN
Is equivalent to the Most Unstable CAPE which is a measure on instability in the tropopause. The Best Cape is calculated by averaging the potential temperature and water vapor mixing ratio in the lowest levels of the model. The most unstable layer is chosen and this parameter should be used to help diagnose where the most unstable air is.
Best LI
The Best Lifted Index is derived from calculating the Lifted Index from each of the "boundary" layers in the model and taking the most unstable or "Best" Lifted index. Note: Best LI does not consider such things as the capping inversion which could limit or prevent the convection from developing. This parameter should be used to help diagnose where the most unstable air is.
1 Hour Precipitation
The one hour precipitation accumulation developed from the forecast model.
6 Hour Precipitation
The six hour precipitation accumulation developed from the forecast model.
12 Hour Precipitation
The twelve hour precipitation accumulation developed from the forecast model.
Composite Reflectivity
Simulated Composite Reflectivity has a great advantage in that it displays detailed mesoscale and near-stormscale structures capable of being forecast by finer resolution models, such as lake-effect snowbands, the structure of deep convection, and frontal precipitation bands. (Koch, 2005)
Freezing Level
Clouds
The effects of the clouds are entirely prognosed from predicted fields: water vapor, cloud water and ice, and frozen and liquid precipitation. Values are given in percent where 0% is totally clear skies and 100% is totally overcast.