000
FNUS21 KWNS 201650
FWDDY1
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1149 AM CDT FRI MAY 20 2011
VALID 201700Z - 211200Z
...CRITICAL FIRE WEATHER AREA FOR ERN PLAINS OF NM...TX SOUTH
PLAINS...AND PERMIAN BASIN...
...PORTIONS OF CNTRL AND ERN NM / WRN TX...
NO MAJOR CHANGES HAVE BEEN MADE TO THE CRITICAL AREA OR THE ONGOING
FORECAST. MODEST LOW/MID-LEVEL WLY FLOW ON THE BACKSIDE OF A
SHORTWAVE TROUGH CURRENTLY SHIFTING EWD ACROSS TX IS EVIDENT IN
RECENT TUCUMCARI NM PROFILER DATA...WHICH IS DEPICTING SPEEDS OF 20
TO 30 MPH IN THE LOW-TO-MID LEVELS. OBSERVATIONS SUGGEST THAT THIS
FLOW IS BEING MANIFESTED IN SUSTAINED WLY WINDS OF 15 TO 25 MPH AT
THE SFC ACROSS PORTIONS OF E-CNTRL NM. WHILE THE MID-LEVEL FLOW IS
FORECAST TO GRADUALLY SUBSIDE LATER TODAY IN THE WAKE OF THE
DEPARTING SHORTWAVE...MULTI-MODEL CONSENSUS SUGGESTS THAT THE SFC
PRESSURE GRADIENT WILL REMAIN SUFFICIENTLY TIGHT TO THE SW OF
DEVELOPING LOW PRESSURE OVER THE TX/OK PANHANDLES TO SUPPORT WLY
WINDS AROUND 20 MPH...WITH LOCALLY HIGHER GUSTS ANTICIPATED.
ADDITIONALLY...AS TEMPERATURES WARM INTO THE UPPER 70S TO UPPER
80S...EXCEPT TO NEAR 90 DEGREES ACROSS PORTIONS OF SERN NM AND SWRN
TX...RH VALUES ARE EXPECTED TO FALL INTO THE MIDDLE SINGLE DIGITS TO
LOWER TEENS. THESE FACTORS...COMBINED WITH THE EXTREME TO
EXCEPTIONAL DROUGHT IN MANY AREAS...WILL YIELD LOWER-END CRITICAL
CONDITIONS TODAY ACROSS THE ERN PLAINS OF NM...TX SOUTH PLAINS...AND
PERMIAN BASIN.
TWO AREAS OF ELEVATED FIRE WEATHER CONDITIONS SURROUNDING THE
CRITICAL AREA COULD DEVELOP:
1. TO THE WEST OF THE CRITICAL AREA ACROSS PORTIONS OF CNTRL
NM...WLY TO WNWLY WINDS AROUND 20 MPH WITH HIGHER GUSTS ARE
ANTICIPATED TODAY IN RESPONSE TO THE AFOREMENTIONED SFC PRESSURE
GRADIENT. HOWEVER...RH VALUES ARE ONLY EXPECTED TO FALL INTO THE
UPPER TEENS TO UPPER 20S IN RESPONSE TO RELATIVELY COOLER
TEMPERATURES IN THE WAKE OF A PACIFIC COLD FRONT...PRECLUDING THE
NEED FOR WWD EXPANSION OF CRITICAL DELINEATION.
2. TO THE EAST AND SOUTH OF THE CRITICAL AREA ACROSS PORTIONS OF WRN
TX...RH VALUES ARE EXPECTED TO FALL INTO THE MIDDLE SINGLE DIGITS TO
THE MIDDLE TEENS. HOWEVER...SUSTAINED WIND SPEEDS ARE EXPECTED TO
REMAIN BELOW 20 MPH WITH THE TIGHTER PRESSURE GRADIENT DISPLACED
FARTHER WEST AND NORTH. ADDITIONALLY...PRECIPITATION DEPOSITED BY
SHOWERS AND THUNDERSTORMS THAT DEVELOPED FROM THE ERN TX PANHANDLE
TO THE EDWARDS PLATEAU EARLIER THIS MORNING WILL FURTHER MITIGATE
THE FIRE WEATHER POTENTIAL EAST OF THE CRITICAL AREA. FOR THESE
REASONS...EWD/SWD EXPANSION OF THE CRITICAL AREA IS NOT NECESSARY.
...SWRN GA...SERN AL...INTERIOR SECTIONS OF THE FL PANHANDLE AND NRN
FL PENINSULA...
A POCKET OF DEEP-LAYER DRY AIR ENCOMPASSING PORTIONS OF AL...SWRN
GA...AND NRN FL IS CHARACTERIZED BY PRECIPITABLE WATER VALUES OF 0.8
TO 1.0 INCH PER AMSU/SSMI BLENDED TOTAL PRECIPITABLE WATER PRODUCT.
THIS RELATIVELY DRY AIR IS BEING SUPPORTED BY SUBSIDENT NWLY FLOW
ALOFT EAST OF A MID-LEVEL RIDGE AXIS OVER THE TN AND LOWER MS VALLEY
REGIONS. AS TEMPERATURES WARM INTO THE UPPER 80S TO LOWER 90S...AND
DRY AIR ALOFT IS MIXED TO THE SFC WITHIN THE DEEPENING MIXED
LAYER...RH VALUES ARE EXPECTED TO FALL INTO THE MIDDLE 20S TO LOWER
30S. THIS COULD YIELD AN ELEVATED FIRE WEATHER THREAT...ESPECIALLY
IN AREAS WHERE PRECIPITATION HAS BEEN LACKING DURING THE LAST COUPLE
OF WEEKS. HOWEVER...THE RELATIVELY WEAK SFC PRESSURE GRADIENT IS
EXPECTED TO KEEP SLY TO SWLY WINDS AOB 10 MPH...THUS MINIMIZING THE
WIND-DRIVEN FIRE THREAT.
..COHEN.. 05/20/2011
.PREV DISCUSSION... /ISSUED 0209 AM CDT FRI MAY 20 2011/
...SYNOPSIS...
MID-UPPER LOW OVER THE N-CNTRL HIGH PLAINS WILL MOVE LITTLE DURING
THE PERIOD. DOWNSTREAM...AN UPPER RIDGE FROM THE NRN GULF COAST
STATES TO GREAT LAKES WILL BE IN BETWEEN THE UPPER LOW TO THE WEST
AND AN UPPER LOW OVER THE NORTHEAST MEGALOPOLIS. IN THE LOW
LEVELS...A COLD FRONT/DRYLINE WILL SLOWLY PUSH E OVER THE SRN PLAINS
/LIKELY MODULATED BY EARLY MORNING TSTM ACTIVITY/ AS UPPER FLOW
ACROSS THE CNTRL-SRN PLAINS STATES BECOMES MERIDIONAL. DRY/WARM
AIRMASS OF CONTINENTAL ORIGIN TO THE W OF THE SURFACE BOUNDARY WILL
SUPPORT LOWER-END CRITICAL FIRE WEATHER CONDITIONS ACROSS PORTIONS
OF THE SRN HIGH PLAINS.
...ERN PLAINS OF NM / TX SOUTH PLAINS - PERMIAN BASIN...
FIRE WEATHER SUPPORTIVE CONDITIONS WILL BE BOUNDED ON THE EAST BY
EARLY MORNING HEAVY RAINFALL THAT EXTENDED ALONG AND E FROM THE
MIDLAND TX VICINITY TO THE SW OK/NW TX BORDER. TO THE W OF THE
AREAS IMPACTED BY RAINFALL...SUNNY SKIES AND A DRY LOW LEVEL AIRMASS
WILL LEAD TO QUICKLY WARMING TEMPS INTO THE 80S AND LOWER 90S ACROSS
THE REGION. THIS WILL RESULT IN RH FALLING INTO THE MIDDLE SINGLE
DIGITS TO LOWER TEENS. FORECAST SOUNDINGS GENERALLY SHOW ONLY
MODESTLY STRONG BOUNDARY LAYER WINDS SPEEDS /I.E. 20 KTS/ BUT SHOULD
RESULT IN SUSTAINED WINDS APPROACHING 20 MPH WITH HIGHER GUSTS.
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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