Fire Weather Outlook Discussion
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FNUS28 KWNS 271858
FWDD38

DAY 3-8 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0158 PM CDT MON APR 27 2015

VALID 291200Z - 051200Z

MEDIUM RANGE GUIDANCE REMAINS IN GENERAL AGREEMENT REGARDING
SYNOPTIC-SCALE UPPER FEATURES THROUGH D5/FRI. GENERALLY SUB-CRITICAL
FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE CONUS...WITH SOME
ELEVATED CONCERNS POSSIBLE ACROSS VARIOUS PORTIONS OF THE HIGH
PLAINS FROM D3/WED THROUGH D7/SUN.

AN UPPER TROUGH-RIDGE-TROUGH PATTERN ACROSS THE CONUS ON D3/WED
SHOULD EVOLVE INTO AN AMPLIFIED LONGWAVE TROUGH OVER THE ERN U.S...A
SHORTWAVE TROUGH OVER THE NWRN STATES...AND A FLATTENED RIDGE OVER
THE DESERT SOUTHWEST BY D4/THU. THEREAFTER...MULTIPLE SHORTWAVE
TROUGHS SHOULD MOVE ACROSS THE NRN PORTIONS OF THE CONUS...WITH MORE
ZONAL FLOW OVER THE CNTRL/SWRN U.S. THROUGH D6/SAT. AN UPPER TROUGH
MAY APPROACH SRN CA AND THE DESERT SOUTHWEST ON D7/SUN INTO D8/MON.

AT THE SFC...PERIODS OF STRONG/GUSTY DOWNSLOPE WINDS MAY OCCUR ON
MULTIPLE DAYS ACROSS PORTIONS OF THE HIGH PLAINS...MAINLY IN
ASSOCIATION WITH SUCCESSIVE SHORTWAVE TROUGHS MOVING OVER THE NRN
TIER OF STATES. THE LIFT AHEAD OF ONE SUCH TROUGH OVER THE PACIFIC
NORTHWEST ON D3/WED SHOULD INDUCE A SFC LOW OVER SASKATCHEWAN
CANADA. AN INCREASED SFC PRESSURE GRADIENT BETWEEN THE LOW AND HIGH
PRESSURE OVER THE NRN PLAINS WILL PROBABLY RESULT IN SLY WINDS
APPROACHING 20 MPH ACROSS MUCH OF THE NRN HIGH PLAINS WED AFTERNOON.
HOWEVER...RH VALUES ARE NOT CURRENTLY EXPECTED TO FALL BELOW
CRITICAL LEVELS...AND WITH RECENT PRECIPITATION ACROSS THIS REGION
ALONG WITH VEGETATIVE GREENUP BEGINNING...NO DELINEATIONS HAVE BEEN
INTRODUCED FOR D3/WED.

AS MULTIPLE PERTURBATIONS IN THE UPPER FLOW PROGRESS EWD ACROSS THE
NRN U.S...DOWNSLOPE WINDS ASSOCIATED WITH SFC LEE TROUGHING ACROSS
THE CNTRL/NRN HIGH PLAINS MAY OCCUR ON D4/THU AND D5/FRI. AT THIS
TIME...CONFIDENCE IS TOO LOW TO INCLUDE PROBABILITIES FOR EITHER
AFTERNOON OWING TO UNCERTAINTY IN WIND SPEEDS EXCEEDING CRITICAL
CRITERIA...RH VALUES FALLING LOW ENOUGH...AND POSSIBLE PRECIPITATION
ASSOCIATED WITH THE PASSAGE OF SEVERAL SHORTWAVE TROUGHS. FROM
D6/SAT THROUGH D8/MON...CONFIDENCE IN THE TIMING OF SUBSEQUENT
SHORTWAVE TROUGHS IN THE NRN STREAM DECREASES...AS DOES THE
PREDICTABILITY OF ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE NRN/CNTRL HIGH PLAINS. ENHANCED DOWNSLOPE WINDS APPEAR
POSSIBLE NEXT WEEKEND WITH EITHER A SFC LEE TROUGH OR BEHIND A COLD
FRONT FOR THIS REGION...BUT TIMING DIFFERENCES IN SFC FEATURES
BETWEEN VARIOUS MODELS PRECLUDE ANY DELINEATIONS AT THIS TIME.

..GLEASON.. 04/27/2015

...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...



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