RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Fri Apr 18 10:56:02 UTC 2014.
No Mesoscale Discussions are in effect as of Fri Apr 18 10:56:02 UTC 2014.
SPC 0730Z Day 3 Outlook
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0204 AM CDT FRI APR 18 2014
VALID 201200Z - 211200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
ISOLATED STRONG...OR POSSIBLY SEVERE...THUNDERSTORMS SHOULD DEVELOP
ALONG A DRYLINE ACROSS THE SOUTHERN HIGH PLAINS FROM WEST TEXAS INTO
WESTERN OKLAHOMA.
...SOUTHERN/CENTRAL HIGH PLAINS...
LOW-LATITUDE SHORT-WAVE TROUGH IS EXPECTED TO PROGRESS ACROSS THE
SRN ROCKIES INTO THE HIGH PLAINS OF WEST TX SUNDAY AFTERNOON.
MID-LEVEL FLOW IS SEASONALLY WEAK WITH THIS FEATURE AS 500 MB
GRADIENT IS NOT PARTICULARLY TIGHT. AS A RESULT...FLOW WITHIN THE
BASE OF THE TROUGH...EXTENDING INTO THE TX SOUTH PLAINS...IS
EXPECTED TO BE ON THE ORDER OF 30KT. EVEN SO...SHORT WAVE IS
EXPECTED TO INDUCE LARGE-SCALE ASCENT ALONG CONVERGENT DRYLINE BY
AFTERNOON THAT SHOULD FOCUS DEEP CONVECTION.
LATEST THINKING IS MODIFIED BOUNDARY LAYER MOISTURE SHOULD GRADUALLY
ADVANCE NWD ACROSS THE WRN GULF BASIN INTO THE HIGH PLAINS WHERE SFC
DEW POINTS ARE EXPECTED TO RISE THROUGH THE 50S. AS TEMPERATURES
WARM INTO THE LOWER 80S BOUNDARY LAYER PARCELS SHOULD FREELY CONVECT
ALONG DRY LINE...MOST LIKELY BY 22Z. FORECAST SOUNDINGS SUGGEST
HIGH-BASED TSTMS SHOULD EVOLVE WHERE SFC-6KM BULK SHEAR COULD
APPROACH 35KT NEAR THE RIO GRANDE RIVER...DROPPING TO NEAR 20KT
ACROSS NWRN OK. WILL INTRODUCE 5 PERCENT SEVERE PROBS TO ACCOUNT
FOR A FEW SLOW-MOVING SUPERCELLS THAT COULD PRODUCE HAIL AND GUSTY
WINDS.
CONVECTION SHOULD ALSO DEVELOP FARTHER NORTH ACROSS KS IMMEDIATELY
AHEAD OF SFC LOW...STRETCHING NEWD ALONG WARM FRONT INTO IA.
FORECAST DEEP LAYER SHEAR IS QUITE WEAK ALONG THIS CORRIDOR AND FOR
THIS REASON HAVE OPTED TO MAINTAIN LESS THAN 5 PERCENT SEVERE PROBS.
IF SUFFICIENT MOISTURE/INSTABILITY CAN RETURN TO THIS REGION THEN
LOW SEVERE PROBS MAY BE ADDED TO ACCOUNT FOR HAIL/WIND POTENTIAL
WITH SLOW-MOVING TSTMS ACROSS THE CNTRL PLAINS.
..DARROW.. 04/18/2014
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Day 4-8 Outlook
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0331 AM CDT FRI APR 18 2014
VALID 211200Z - 261200Z
...DISCUSSION...
EARLY IN THE MEDIUM-RANGE PERIOD BOTH THE GFS AND ECMWF ARE IN
GENERAL AGREEMENT REGARDING THE MOVEMENT OF LOW-LATITUDE SHORT-WAVE
TROUGH AS IT SHIFTS EAST OF THE SRN PLAINS INTO THE LOWER MS VALLEY.
25-35KT NW H5 FLOW ON BACK SIDE-BASE OF THIS FEATURE WILL ENHANCE
DEEP-LAYER SHEAR COINCIDENT WITH MODEST INSTABILITY. STRONG HEATING
WILL LIKELY DEVELOP ACROSS THE HILL COUNTRY OF TX AND DAYTIME
HEATING COULD PROVE INSTRUMENTAL IN A FEW SUPERCELLS IN THE WAKE OF
SHORT WAVE. GIVEN THAT THIS ACTIVITY WOULD EVOLVE WITHIN A BROADER
ZONE OF LESS THAN FAVORABLE LARGE-SCALE ASCENT...COVERAGE SHOULD BE
INADEQUATE TO WARRANT 30 PERCENT SEVERE PROBS DURING THE DAY4
PERIOD.
LATER IN THE WEEK MODEL SOLUTIONS BEGIN TO DIVERGE A BIT AS
LARGE-SCALE PATTERN CHANGES. ECMWF IS CONSIDERABLY FASTER THAN THE
GFS ALLOWING A STRONG SHORT-WAVE TROUGH TO TRANSLATE INTO THE
ROCKIES BY WEDNESDAY. DIFLUENT FLOW ALOFT AND STRENGTHENING SHEAR
PROFILES WOULD PROVE POTENTIALLY FAVORABLE FOR A PLAINS SEVERE
EVENT. HOWEVER...GFS DOES NOT EJECT THIS FEATURE UNTIL LATER
THURSDAY. EITHER OF THESE SOLUTIONS COULD GENERATE A POTENTIALLY
SIGNIFICANT SEVERE EVENT BUT TIMING DIFFERENCES PREVENT DELINEATING
AN ORGANIZED SEVERE THREAT THIS PERIOD.
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SPC Day 1 Fire Weather Outlook
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0217 AM CDT FRI APR 18 2014
VALID 181200Z - 191200Z
...SYNOPSIS...
A SRN STREAM UPPER LOW APPROACHING THE SRN CA COAST WILL SLOWLY MOVE
EWD...WITH A PLUME OF MIDLEVEL MOISTURE OVERSPREADING THE SOUTHWEST
AND SRN ROCKIES. NRN STREAM WILL REMAIN MORE ACTIVE AS A SERIES OF
PROGRESSIVE SHORTWAVE TROUGHS MOVE ACROSS THE NRN ROCKIES AND UPPER
GREAT LAKES. AT THE SFC...SLY FLOW WILL DEVELOP ACROSS THE PLAINS ON
THE WRN PERIPHERY OF HIGH PRESSURE CENTERED NEAR THE MS VALLEY...AND
LOW PRESSURE WILL DEEPEN ACROSS THE DAKOTAS.
...FOUR CORNERS AREA...
MODEST MIDLEVEL MOISTENING AHEAD OF THE AFOREMENTIONED PACIFIC LOW
WILL CONTRIBUTE TO PW VALUES INCREASING TO AROUND 0.4-0.5 INCH.
STRONG SFC HEATING WILL ALLOW MARGINAL DESTABILIZATION TO
OCCUR...SUPPORTING THE DEVELOPMENT OF A FEW AFTERNOON/EVENING TSTMS.
THE BOUNDARY-LAYER WILL REMAIN QUITE DRY...SO ANY TSTMS THAT DEVELOP
WILL LIKELY PRODUCE LITTLE TO NO PRECIPITATION. TSTM COVERAGE IS
FORECAST TO REMAIN TOO SPARSE TO WARRANT A CRITICAL DRY TSTM RISK.
..ROGERS.. 04/18/2014
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0218 AM CDT FRI APR 18 2014
VALID 191200Z - 201200Z
...NO CRITICAL AREAS...
...SYNOPSIS...
A SLOW-MOVING SRN-STREAM SHORTWAVE TROUGH WILL CONTINUE TO PROGRESS
EWD ACROSS THE SOUTHWEST...WHILE STRONGER WLY FLOW ALOFT REMAINS
DISPLACED NWD NEAR THE CANADIAN BORDER. SLY WINDS WILL STRENGTHEN
ACROSS THE SRN/CNTRL PLAINS AS A LEE SFC LOW DEEPENS OVER SERN
CO...BUT INCREASING LOW-LEVEL MOISTURE SHOULD LIMIT FIRE WEATHER
CONCERNS. ELSEWHERE...CRITICAL FIRE WEATHER POTENTIAL APPEARS LOW
GIVEN A MODERATELY MOIST AIR MASS ACROSS THE SRN HALF OF THE
NATION...AND A LACK OF APPRECIABLY STRONG SFC WINDS.
..ROGERS.. 04/18/2014
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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