Fort Collins, CO...Greeley, CO...Cheyenne, WY...Lake Jackson, TX...North Platte, NE...
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
30 %
27,923
128,834
Scottsbluff, NE...Torrington, WY...
15 %
183,038
2,393,495
Lubbock, TX...Amarillo, TX...Midland, TX...Odessa, TX...Rapid City, SD...
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
30 %
27,797
127,198
Scottsbluff, NE...Torrington, WY...
15 %
183,175
2,395,078
Lubbock, TX...Amarillo, TX...Midland, TX...Odessa, TX...Rapid City, SD...
5 %
131,693
3,929,526
Omaha, NE...Wichita, KS...Lincoln, NE...Sioux Falls, SD...Fort Collins, CO...
SPC AC 151954
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0254 PM CDT FRI MAY 15 2015
VALID 152000Z - 161200Z
...THERE IS AN ENH RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
ACROSS PARTS OF SOUTHEAST WYOMING...SOUTHERN SOUTH DAKOTA AND
WESTERN NEBRASKA...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SURROUNDING NORTH
CENTRAL HIGH PLAINS...AND SOUTHWARD ACROSS THE CENTRAL INTO SOUTHERN
HIGH PLAINS FOR LATE THIS EVENING INTO THE OVERNIGHT HOURS...
...THERE IS A MRGL RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
CENTRAL AND SOUTHERN PLAINS...AND ACROSS PARTS OF THE MID MISSOURI
INTO MIDDLE MISSISSIPPI VALLEY...
...THERE IS A MRGL RISK OF SVR TSTMS LATE THIS AFTERNOON ACROSS
PARTS OF TEXAS COASTAL AREAS...
...SUMMARY...
SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING ACROSS
PARTS OF THE NORTH CENTRAL HIGH PLAINS...WHERE LARGE HAIL...DAMAGING
GUSTS...AND A COUPLE OF TORNADOES ARE POSSIBLE. ADDITIONAL STRONG
TO SEVERE STORMS ARE POSSIBLE ACROSS PARTS OF THE CENTRAL AND
SOUTHERN HIGH PLAINS LATE THIS EVENING OR OVERNIGHT.
...20Z OUTLOOK UPDATE...
ADJUSTMENTS HAVE BEEN MADE TO THE CATEGORICAL AND PROBABILISTIC
LINES IN AN ATTEMPT TO ACCOUNT FOR ONGOING CONVECTIVE TRENDS AND
DESTABILIZATION.
...LOWER GREAT LAKES/UPPER OHIO VALLEY...
IT IS APPEARING INCREASINGLY UNLIKELY THAT THERE WILL BE SUFFICIENT
LOW-LEVEL MOISTENING AND DESTABILIZATION TO SUPPORT AN APPRECIABLE
SEVERE WEATHER THREAT...BEFORE MODEST VERTICAL SHEAR WEAKENS IN THE
WAKE OF THE SHORT WAVE IMPULSE MIGRATING THROUGH THE LOWER GREAT
LAKES REGION.
...TEXAS COASTAL AREAS...
LOW PROBABILITIES FOR SEVERE WIND GUSTS...AND PERHAPS A BRIEF/WEAK
TORNADO...ARE BEING MAINTAINED FOR VIGOROUS CONVECTIVE DEVELOPMENT
ALONG AN EASTWARD ADVANCING CONVECTIVELY GENERATED COLD POOL...
SPREADING TOWARD UPPER TEXAS COASTAL AREAS...AND SOUTHWARD ACROSS
DEEP SOUTH TEXAS COASTAL AREAS.
...MID MISSOURI INTO MIDDLE MISSISSIPPI VALLEY...
LOCALIZED STRONG WIND GUSTS MAY NOT BE OUT OF THE QUESTION THROUGH
WITH AN ONGOING ARCING BAND OF STORMS WHICH SHOULD OVERSPREAD THE
REGION THROUGH THE REMAINDER OF THE AFTERNOON.
...HIGH PLAINS...
NO APPRECIABLE CHANGES HAVE BEEN MADE. PRIMARY SEVERE THUNDERSTORM
RISK SHOULD REMAIN FOCUSED ACROSS THE NORTH CENTRAL HIGH PLAINS LATE
THIS AFTERNOON AND EVENING. FARTHER SOUTH...ANYTHING MUCH BEYOND
THE LOWER THRESHOLD SEVERE PROBABILITIES /5 PERCENT/ STILL SEEMS
LIKELY TO AWAIT FORCING FOR ASCENT ASSOCIATED WITH A SHORT WAVE
IMPULSE CURRENTLY STILL WEST OF THE SOUTHERN ROCKIES. THIS MAY NOT
OCCUR UNTIL AFTER 16/03Z... PERHAPS AFTER 06Z...AT A TIME WHEN
RADIATIONAL SURFACE COOLING WILL BEGIN IMPACTING BOUNDARY LAYER
INSTABILITY ALONG THE RETREATING DRYLINE.
..KERR.. 05/15/2015
.PREV DISCUSSION... /ISSUED 1130 AM CDT FRI MAY 15 2015/
...CENTRAL HIGH PLAINS THIS AFTERNOON INTO TONIGHT...
A LARGE-SCALE TROUGH OVER THE SRN GREAT BASIN WILL PROGRESS SLOWLY
EWD WHILE DOWNSTREAM RIDGING ALOFT PERSISTS OVER THE MS/OH VALLEY
REGION. A SERIES OF EMBEDDED SPEED MAXIMA WILL ROTATE EWD AND NWD
AROUND THE ERN PERIPHERY OF THE TROUGH...WITH ONE SUBTLE SPEED MAX
TRANSLATING NNEWD OVER CO...AND A STRONGER UPSTREAM WAVE OVER NRN
BAJA CA THAT WILL REACH THE SRN HIGH PLAINS LATE TONIGHT. AT THE
SURFACE...A LEE CYCLONE WILL CONTINUE TO DEEPEN SOME THROUGH THE
AFTERNOON ACROSS NE CO...AND A WARM FRONT WILL MOVE NWD INTO NEB.
THE MOISTURE PATTERN IN THE LOW LEVELS HAS BEEN DISRUPTED BY THE
EFFECTS OF OVERNIGHT CONVECTION ACROSS KS/OK...WITH SUBSTANTIAL
DRYING NOTED ACROSS WRN KS. THIS DRIER LOW-LEVEL AIR WILL SPREAD
NWD INTO SW NEB TODAY AND WILL TEND TO OFFSET DESTABILIZATION DUE TO
DAYTIME HEATING...WHILE SOMEWHAT HIGHER DEWPOINTS WILL BE MAINTAINED
FROM SE NEB INTO ERN KS WHERE SURFACE TEMPERATURES WILL BE SLOWER TO
WARM AS A RESULT OF LINGER CLOUDS/CONVECTION.
AS THE SPEED MAX MOVES NNEWD OVER CO...THUNDERSTORM DEVELOPMENT IS
EXPECTED NEAR AND N OF THE LEE CYCLONE BY EARLY-MID AFTERNOON FROM
N/NE CO INTO SE WY AND THE NEB PANHANDLE. BOUNDARY LAYER DEWPOINTS
IN THE LOW-MID 50S AND SURFACE TEMPERATURES WARMING INTO THE
70S...BENEATH STEEP MIDLEVEL LAPSE RATES...WILL RESULT IN MODERATE
BUOYANCY THIS AFTERNOON /MLCAPE VALUES APPROACHING 2000 J PER KG/.
COINCIDENT WITH THE DESTABILIZATION...DEEP-LAYER VERTICAL SHEAR WILL
BECOME FAVORABLE FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL AND
DAMAGING WINDS. SOME UPSCALE GROWTH INTO CLUSTERS/LINE SEGMENTS
WILL BE POSSIBLE BY THIS EVENING AS STORMS OVERSPREAD SW SD.
LOW-LEVEL SHEAR AND MOISTURE WILL BE SUFFICIENT FOR A COUPLE OF
TORNADOES WITH THE MORE DISCRETE SUPERCELLS LATER THIS AFTERNOON.
...DRYLINE FROM WRN KS TO THE TX PANHANDLE TONIGHT...
WHILE ISOLATED/SHORT-LIVED STORMS WILL BE POSSIBLE ALONG THE DIFFUSE
DRYLINE THIS AFTERNOON FROM WRN KS TO THE ERN TX PANHANDLE...THE
GREATER RISK FOR MORE WIDESPREAD CONVECTION WILL BE TONIGHT AS A
PACIFIC COLD FRONT ENCOUNTERS THE RETREATING DRYLINE. ASCENT OVER
THE SRN HIGH PLAINS WILL BE AUGMENTED IN THE EXIT REGION OF THE
SPEED MAX APPROACHING FROM NRN BAJA...AND THE WWD ADVANCE OF THE
LOW-LEVEL MOISTURE WILL RESULT IN MODERATE BUOYANCY AND ONLY SMALL
CONVECTIVE INHIBITION...GIVEN THE LACK OF AN UPSTREAM WARM ELEVATED
MIXED LAYER. STORMS THAT FORM TONIGHT ALONG THE DRYLINE/COLD FRONT
WILL SUBSEQUENTLY MOVE EWD/NEWD ACROSS THE TX PANHANDLE AND SW
KS...WITH AN ATTENDANT RISK FOR AT LEAST ISOLATED LARGE HAIL AND
DAMAGING GUSTS.
...ERN KS/SE NEB/SRN IA/MO THIS AFTERNOON...
AN MCV WITH ONGOING CONVECTION WILL MOVE NNEWD TOWARD NW MO THROUGH
THE AFTERNOON. SURFACE HEATING IN CLOUD BREAKS OVER MO ALONG AND S
OF A STALLED SURFACE FRONT WILL SUPPORT MLCAPE VALUES NEAR 2000 J/KG
BASED ON MODIFIED 12Z SOUNDINGS FROM TOP/SGF. VERTICAL SHEAR WILL
BE RELATIVELY WEAK...BUT A FEW PULSE-TYPE STORMS WITH MARGINALLY
SEVERE HAIL AND DOWNBURST WINDS WILL BE POSSIBLE THROUGH THE
AFTERNOON ACROSS CENTRAL/NRN MO. ISOLATED HAIL APPROACHING ONE INCH
IN DIAMETER MAY ALSO OCCUR WITH ELEVATED CONVECTION FARTHER N FROM
SE NEB INTO SRN IA.
...S TX THIS AFTERNOON...
AN ONGOING MCS OVER S CENTRAL TX WILL LIKELY PERSIST THROUGH THE
AFTERNOON WHILE DEVELOPING EWD/SEWD INTO A MOIST AND MODERATELY
UNSTABLE ENVIRONMENT. VERTICAL SHEAR WILL BE SUFFICIENT FOR SOME
STORM-SCALE ORGANIZATION...WITH ISOLATED DAMAGING GUSTS AND
MARGINALLY SEVERE HAIL THE MAIN CONCERNS.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z