Last updated on 12/05/04

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  Here are a few forecasting tips that will hopefully help you when trying to get an idea of that target area. Scroll down to the bottom of the page for links to popular forecasting sites.


 Look for 850mb winds of 25 knots or more.

 Look for 850mb Td of 10 degrees C or more.

 Look for 500mb winds of 40 knots or more.

 A 500mb temp of -6C or higher will suppress vigorous convection.

 When the 700mb temp is 14C or higher T-storm activity is unlikely without a major triggering mechanism.

 You need dry air at 700mb for supercell development. A T-Td spread more than 5C with a Td less than 0C.

 Look for 300mb winds of 70 knots or more.

 Look for a 45 degree veering of winds between the surface and 700mb.

 In May, June look for 500mb temps of -13C or colder for severe WX.

 In March, April, and October look for 500mb temps of -15C or colder for severe WX.

 Look for a surface pressure of 1005mb or less.

 Look for a freezing level of 615mb or lower for large hail.

 The CCL should be below 780mb.

 The LFC should be below 660mb.

On 850 mb maps Look for convergence, divergence, confluence, and diffluence.

 Air rises due to low level convergence and confluence.

 Low level warm air advection contributes to synoptic scale rising air; Low level cold air advection contributes to synoptic scale sinking air.

 850 mb Chart is good for assessing low level warm air and cold air advection.

 A vertical velocity of 6 -ub/s is significant while a vertical velocity of 10 or greater is very significant (also need moisture!).

 The main objective when looking at 850 mb charts is to look for WAA and CAA.

 The main objective when looking at 500 mb charts is vorticity.

 A rough guide to the intensity of a vort max is: less than 14: small vorticity; 14 to 20: moderate; 22+ large. The value of the vorticity maximum does not tell the whole story. For strong upward motion to result with a vort max, there must also be a strong wind flow (long wind vectors) flowing through the vort max.

 A FRZ level with a pressure level of 650 mb or closer to the surface in a severe weather situation generally will support large hailstones.

 A negatively tilted trough is a trough that is oriented from the NW to the SE.

 A positively tilted trough is a trough that is oriented from the NE to the SW.

 Shortwaves are best examined on the 700 and 500 millibar charts.

 The 500 millibar chart is one of the best charts for studying the following: vorticity advection, the trough/ridge pattern, and shortwaves.

 Jet streaks within the jet stream cause air, which is closer to the surface of the earth, to rise due to a vacuum effect the jet streaks create. As a jet streak enters into a trough, it can energize the trough causing the low pressure to deepen and heights to fall. A strong jet streak will have winds of 120 knots or greater.

 The atmosphere can become thermodynamically unstable by solar heating of the earth's surface.

 Adding moisture to the low levels of the atmosphere makes the atmosphere more unstable.

 Low level instability can be rapidly brought about by warm air along with moisture advection (bringing of a warm and humid airmass into a region).
 Cooling the middle and upper levels of the atmosphere causes the atmosphere to become more unstable.

 Strong speed and directional wind shear can cause the atmosphere to become more unstable. Examples include: Jet streaks, vorticity, low level jet, low level horizontal vorticity.

 Cold air advection into the midlevels of the atmosphere and warm air advection into the low levels can also lead to a steep (much greater than normal) lapse rate. A steep lapse rate is indicative of an unstable atmosphere.

 For severe weather to be associated with cold fronts, look for the following: high dewpoints ahead of the front (60 F or greater), strong upper level winds (300 mb wind greater than 120 knots), front movement between 10 and 20 mph, and convergence along the front. Storms tend to be strongest on the southwest edge of the frontal boundary due to a combination of the following: higher dewpoints, more convective instability, cap breaks there last, uninhibited inflow into storms, storms are generally more isolated and thus realize more convective energy.

 WARM FRONTS: Severe weather generally occurs on the warm side of the warm front but is most favorable in the vicinity of the warm front boundary. This is due to the fact that the greatest directional wind shear is located along the warm front boundary. When storm chasing warm front convection, a good location would be to stay near the warm front boundary while at the same time being relatively close to the mid-latitude cyclone which connects to the warm front. As a general rule, severe weather is not as common along warm front boundary as compared to out ahead of cold front boundaries for these reasons: A smaller frontal slope results in less frontal convergence, east of the Rockies convective instability (dry air in mid-levels) is not as well defined with warm fronts, convection tends to be more horizontally slanted, the temperature gradient from one side of the frontal boundary to the other is generally less in association with warm fronts.

 DRYLINES: The higher the dewpoint gradient from one side of the dryline to the other is a good indication of dryline intensity. Critical point: No convergence along the dryline results in NO storms. Drylines are most common in the high plains in the Spring and early Summer. Certain factors must be in place for a dryline to produce severe convection. As mentioned, the most critical is convergence. This convergence can be intensified by a combination of the following: Strong upper level winds overriding the dryline (can produce dryline bulge), warm moisture rich air being advected directly toward the dryline boundary (e.g. 850 mb Southeast wind at 30 knots ahead of the dryline, West wind at 35 knots behind dryline), and a upper level trough. Severe storms in association with drylines tend to be classic or LP supercells. The shallowness of moist air ahead of the dryline boundary limits the amount of PW and moisture the storms can convect. The cap is critical to determining if a dryline will produce storms. If convergence is not strong enough, the cap (inversion above PBL) will prevent convection from occurring. Strong convergence will break the cap. Generally, drylines are most intense and significant when a mid-latitude cyclone over the High or Great Plains forces warm moist air from the Gulf and dry air from the high plains to advect over the top of the warm moist air.

 Why is a moisture tongue important?

 1. They are associated with low level instability. Warm and moist PBL air enhances a large thermodynamic instability.

 2. The high speed air associated with a moisture tongue fuels developing thunderstorms by producing a large storm relative inflow and helicity (speed and directional shear in the PBL).

 3. Warm air advection and moisture advection are a dynamic lifting mechanism (warm moist air is less dense which causes a stretching and subsequent dynamic lifting of the low levels of the atmosphere).

 4. Since a moisture tongue is a region of instability, thunderstorms often develop and become strongest within the moisture tongue region.

 5. Precipitable Water values (PWs) will be higher in the moisture tongue.

 6. Isentropic lifting of a moisture tongue can cause widespread precipitation north of a warm front.

 DYNAMIC TRIGGER MECHANISMS: Without a trigger mechanism, such as when a strong cap is present, storms may not form. Here are examples of dynamic trigger mechanisms:
 1. dryline
 2. cold or warm front
 3. outflow boundary
 4. jet streak
 5. strong upper level vorticity
 6. orographic lifting
 7. low level warm air advection (strong gradient of warmer temperature moving toward a fixed point)
 8. Low level jet
 9. Gravity waves
 10. Meso-lows

 PBL WIND SHEAR: Speed shear (wind speed increasing with height in the PBL); directional shear (wind veering, turning clockwise more than 45 degrees in the PBL); Average PBL wind greater than 20 knots (It has been found that for tornadoes to develop the PBL inflow needs to be greater than 20 knots, the higher the better)

The best chart to use when examining the trough / ridge pattern is the 500-millibar chart.

 The atmosphere is most unstable when a large trough in association with a strong mid-latitude cyclone becomes NEGATIVELY TILTED. Why? Because on the right side of the trough, the negative tilt causes cold air advection in the upper levels of the atmosphere while the PBL is warm and humid (especially if this situation occurs east of the Rocky Mountains in the fall or spring). Cold air above warm air creates thermodynamic instability and convective instability. A strong jet streak can cause a trough to become negatively tilted and contributes to dynamic lifting. It is the jet stream and jet streaks that are responsible for causing troughs to become more amplified or less amplified. The jet streaks also contribute to the tilt of a trough. Look at the 500-mb chart each day and see if the troughs over the US are highly or weakly amplified and positive, neutral, or negatively tilted.



  360                                                  N

           75                                                    NE

           90                                                    E

           135                                                  SE

           180                                                  S

           225                                                  SW

           270                                                  W

           315                                                   NW



 CAPE Value                   Degree of Instability

 0-1000                      Marginally Unstable 

 1000-2500                Moderately Unstable

 2500-3500                Very Unstable

 >3500                       Extremely Unstable



 EHI Value                            Supercell/Tornado Potential

 <2.0           Significant mesocyclone-induced tornadoes unlikely to occur

 2.0-2.4      Mesocyclone-induced tornadoes possible, but unlikely to be strong or long-lived

 2.5-2.9      Mesocyclone-induced tornadoes likely

 3.0-3.9      Strong tornadoes (F2-F3) possible

 > 4.0         Violent tornadoes (F4) possible

 NOTE: These guidelines assume mid-level winds > 25 kts and 0-2 km storm-relative inflow > 20 kts


 Lifted Index (oC)                                Degree of Instability

 0 to -3                                        Marginally Unstable

 -3 to -6                                       Moderately Unstable 

 -6 to -9                                       Very Unstable

 Less than -9                               Extremely Unstable


SPC Convective Outlooks

SPC Hourly Mesoscale Analysis Page

SPC Mesoscale Discussions

SPC Forecast Tools

SPC Current Convective Watches

National Weather Service



College of DuPage Weather Lab

Oklahoma Weather Roundup

Unisys Weather

NWS Forecast Maps/Models

HPC Short Range Forecast (Days 1 and 2)

Texas A&M Weather Interface

Real-Time ADAS ARPS Data Analysis System

STORM TRACK Weather Data Page

Texas Forecast Discussions

Oklahoma Forecast Discussions

Kansas Forecast Discussions

New Mexico Forecast Discussions

Colorado Forecast Discussions

Nebraska Forecast Discussions

College of DuPage Wind Profilers

SSEC Infrared Satellite

SSEC Visible Satellite

SSEC Water Vapor Satellite

GOES-10 Visible Satellite Image

Texas A&M Soundings Page

Various Sounding Plots

Skew-T Sounding and Hodograph Plots

College of DuPage Radar Sites

West Texas Mesonet Site

Oklahoma Mesonet Site

Kansas Mesonet Site

Southern Plains Surface Plot

Central Plains Surface Plot

Current Lightning Strikes

Last but not least. This site is probably the best weather site I have ever found on the internet for all around weather knowledge and forecasting. It covers all topics and aspects of forecasting weather and everything in between. Weather

Hopefully these sites will help you to become a better chaser and forecaster!


Abilene 162.400
Amarillo 162.550
Borger 162.400
Dallas 162.400
Lubbock 162.400
Midland/Odessa 162.400
Plainview 162.450
San Angelo 162.550
Wichita Falls 162.475

La Junta 162.500
Lamar 162.525
Springfield 162.400

Dodge City 162.475
Goodland 162.400
Hays 162.400
Meade 162.425
Topeka 162.475
Tribune 162.550
Ulysses 162.450
Wichita 162.550

Albuquerque 162.400
Clovis 162.475
Des Moines 162.550
Hobbs 162.400
Roswell 162.450
Altus 162.425
Ardmore 162.525
Clinton 162.525
Enid 162.475
Lawton 162.550
Oklahoma City 162.400
Stillwater 162.500
Tulsa 162.550
Woodward 162.500

 If you have any forecasting tips you would like to send then please e-mail me and I will post them                                                                                                                             

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This site was last updated 12/05/04

NOTE: Click on what you think is the correct answer and a box will pop up telling you if it's the correct answer or not.
These quizzes are borrowed from the great site of Weather

1. This chart will have the most data available for the operational meteorologist to interpret:

2. All of the following charts have height contours except:

3. This occurs when the downstream wind speeds are faster than the upstream wind speeds:

4. This is a region of high heights:

5. Both of the following promote rising air:

6. If the height contours are parallel to the isotherms, a forecaster would expect:

7. A height contour is also known as an ___________.

8. The strength of thermal advection is determined by the spacing of height contours, the spacing of isotherms and:

9. This side of a shortwave is most likely to have uplift, clouds and precipitation:

10. A region with sinking air and warming of an air mass is most likely to experience:

11. A shortwave that has temperature advections associated with it is a _________ shortwave.

12. As a 700 mb shortwave approaches, a forecaster would expect heights at 700 mb to:

13. This is the type of vorticity generated from wind speeds changing over synoptic scale distances:

14. A vort max will be located at the point where there is:

15. When vorticity advection is occurring, the upward forcing from positive vorticity advection will occur __________ from the axis of highest vorticity.

16. From the answers below, a vorticity maximum is most likely to be found:

17. A weakening trough is one that is:

18. If the 300 mb winds are much stronger in the entrance sector of a trough than they are in the exit sector of a trough, the trough will:

19. On the global scale, the Pressure Gradient Force points from the equator toward the pole in the middle latitudes. What force causes this wind to be deflected from that path of motion to create the typically west to east flowing jet stream aloft in the middle latitudes?:

20. This quadrant is in the entrance sector of a jet streak and dynamic lifting is favorable:

1. For every 10 C the Celsius temperature changes, the Fahrenheit temperature changes by:

2. 50 knots is equal to:

3. 100 miles per hour is equal to:

4. When it is 12 Z in New York City, NY it is also 12 Z in Los Angeles, CA.

5. Central Standard Time occurs in:

6. It turns the next day in the United States before it turns the next day in Europe.

7. This is a line of equal sea level atmospheric pressure change over a given time:

8. A map is showing contours of temperature, dewpoint and height. The contours on the map include:

9. A thickness line is the vertical distance between two:

10. In meteorology, wind direction is expressed as the direction the wind is ____________.

11. Which of the following statements DOES NOT have an error?:

12. A wind from 135 degrees is a ____________ wind.

13. This is the equation used to calculate thickness between two pressure surfaces:

14. This equation relates pressure, density and temperature.

15. When latent heat is absorbed, the surrounding environment:

16. These are both warm core lows:

17. A sign that a cold core low is maturing and can undergo further intensification is when it tilts toward the cold air with height.

18. These two air masses are similar but this one is the coldest and driest:

19. All the following terms mean Planetary Boundary Layer except:

20. When winds are light, the Planetary Boundary Layer will:

1. The mesoscale front that is found along coastlines during the afternoon due to differential heating between land and sea is the:

2. Which of the following is mesoscale in size and time:

3. Instability can generally increase due to:

4. The forecast models have the most difficult time resolving this feature:

5. In this layer of the troposphere, friction is a significant force. In this layer winds tend to be gusty especially at higher wind speeds and convective mixing is common.

6. Surface boundaries that experience a density discontinuity in a thunderstorm situation tend to:

7. A region of high velocity wind in the lower troposphere due to a strong thermal gradient near the cold front boundary is termed the:

8. The warm air advection pattern associated with a baroclinic shortwave tends to occur in the ______ in relation to the shortwave axis.

9. All Mesoscale Convective Complexes are Mesoscale Convective Systems.

10. The temperature will often be warmer behind the dryline as compared to ahead of the dryline in the afternoon due to:

11. A region experiencing strong positive vorticity advection will likely also experience ______________ since rising air cools adiabatically.

12. A region experiencing strong low level warm air advection will likely also experience ____________ since warmer air has a larger volume than the same mass of colder air.

13. The surface wind experienced in the boundary layer is a result of these three forces:

14. The term "meso" means:

15. An increase of boundary layer dewpoints can occur from:

16. In which case could higher elevation regions be warmer than lower elevation regions:

17. The side of a mountain range that has upslope wind and is more likely to have clouds and precipitation is the ____________ side.

18. This is a high speed segment of wind within the Polar jet stream produced by a region of enhanced temperature gradient in the troposphere.

19. Strong mesoscale upward forcing will occur where:

20. On hot sunny days, the temperature over a lake surface tends to be cooler than over a land surface. Why?