Storm Prediction Center Day 2 Fire Weather Outlook
Created: Wed Jun 19 16:34:03 UTC 2013
|
Click for Day 2 FireWX Areal Outline Product (KWNSPFWFD2)
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 191633
DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1133 AM CDT WED JUN 19 2013
VALID 201200Z - 211200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SRN UT...MUCH OF SRN
CO...WRN AND NRN NM...NRN/E-CNTRL AZ...EXTREME SERN NV...
...PORTIONS OF SRN UT...MUCH OF SRN CO...WRN AND NRN
NM...NRN/E-CNTRL AZ...EXTREME SERN NV...
THE CRITICAL AREA WAS EXPANDED EASTWARD TO INCLUDE MUCH OF NRN NM
AND SRN CO. SIMILAR CONDITIONS TO THOSE ON DAY 1/WED ARE EXPECTED
WITH POTENTIALLY SLIGHTLY STRONGER WINDS. OTHERWISE...FORECAST
REASONING REMAINS UNCHANGED. SEE PREVIOUS OUTLOOK FOR MORE DETAILS.
...SURROUNDING THE CRITICAL AREA ACROSS PORTIONS OF SRN NV...SRN/WRN
AZ...SRN NM...WRN PARTS OF THE OK/TX PANHANDLES...SWRN KS...FAR SE
CO...SRN/CNTRL/ERN UT...
NO CHANGES TO THE SEE TEXT AREA OTHER THAN THOSE NOTED ABOVE. PLEASE
SEE PREVIOUS DISCUSSION FOR DETAILS.
...COASTAL RANGES AND ADJACENT FOOTHILLS OF SRN CA FROM THE ERN
TWO-THIRDS OF SANTA BARBARA COUNTY EWD TO NWRN/N-CNTRL LOS ANGELES
COUNTY...
NO CHANGES. SEE PREVIOUS DISCUSSION FOR DETAILS.
..LEITMAN.. 06/19/2013
.PREV DISCUSSION... /ISSUED 0303 AM CDT WED JUN 19 2013/
...SYNOPSIS...
A MID-LEVEL CYCLONE WILL MEANDER ACROSS PARTS OF THE NRN
ROCKIES...WHILE SHORTWAVE TROUGHS EMBEDDED WITHIN THE BROADER AREA
OF FLOW SURROUNDING THE CYCLONE CENTER MAINTAIN MEAN CYCLONIC FLOW
IN THE MID LEVELS ACROSS MUCH OF THE WRN CONUS. ONE SHORTWAVE TROUGH
WILL PIVOT AROUND THE CYCLONE FROM MT INTO ADJACENT SRN
CANADA...WHILE ADDITIONAL SHORTWAVE TROUGHS PIVOT THROUGH THE SRN
AND WRN SEMICIRCLES OF THE CYCLONE. MEANWHILE...A RIDGE WILL BUILD
ACROSS PARTS OF THE CNTRL CONUS. THESE FACTORS WILL MAINTAIN A ZONE
OF ENHANCED TROPOSPHERIC FLOW ACROSS PARTS OF THE WRN STATES...WHICH
WILL OVERLIE DRY SFC CONDITIONS IN SOME LOCATIONS TO SUPPORT A
CRITICAL FIRE WEATHER AREA.
...PORTIONS OF SRN UT...SWRN CO...WRN NM...NRN/E-CNTRL AZ...EXTREME
SERN NV...
THE AFOREMENTIONED ENHANCED TROPOSPHERIC FLOW IS FORECAST TO SUPPORT
SSWLY TO SWLY SFC WINDS OF 20-25 MPH AS VERTICAL MIXING STRENGTHENS
THROUGH THE DAY AND ALLOWS THE STRONGER FLOW ALOFT TO BE MANIFESTED
AT THE SFC. AND...WITH A DRY AIR MASS IN PLACE...RH VALUES ARE
EXPECTED TO FALL TO AROUND 5-10 PERCENT AS STRONG DIURNAL HEATING
SUPPORTS TEMPERATURES RISING INTO THE 80S AND 90S. THE PRESENCE OF
DRY/VERY DRY FUELS WILL EXACERBATE THE FIRE WEATHER
THREAT...RESULTING IN CRITICAL FIRE WEATHER DESIGNATION.
...SURROUNDING THE CRITICAL AREA ACROSS PORTIONS OF SRN NV...SRN/WRN
AZ...SRN/CNTRL/ERN/NRN NM...WRN PARTS OF THE OK/TX PANHANDLES...SWRN
KS...SRN/WRN CO...SRN/CNTRL/ERN UT...
----STRONG WIND/LOW RH POTENTIAL----
RH VALUES ARE EXPECTED TO BECOME CRITICALLY LOW IN MANY AREAS TO THE
W OF A CNTRL/SRN-HIGH-PLAINS LEE TROUGH WHERE A DRY AIR MASS WILL BE
PRESENT. BOUNDARY-LAYER HEATING AND DRYING WILL BE EXACERBATED BY
DOWNSLOPE FLOW IN THE LEE OF THE ROCKIES. ELEVATED TO PERHAPS
BORDERLINE CRITICAL FIRE WEATHER CONDITIONS ARE ANTICIPATED...AS SLY
TO SWLY SFC WINDS INCREASE TO 15 TO AROUND 20 MPH THROUGH THE DAY.
HOWEVER...CONFIDENCE IN CRITICALLY STRONG SUSTAINED WIND SPEEDS
OCCURRING ON ANY MORE THAN A BRIEF/SPOTTY BASIS OUTSIDE OF THE
CRITICAL AREA IS LIMITED OWING TO LOW CONFIDENCE IN STRONGER
LOW/MID-LEVEL FLOW BEING PRESENT. AS SUCH...CRITICAL DESIGNATION HAS
NOT BEEN INCLUDED AT THIS TIME.
----DRY-THUNDERSTORM POTENTIAL IN SRN NM----
AS THE MID-LEVEL RIDGE BUILDS ACROSS PARTS OF THE CNTRL CONUS...THE
SLY FLOW COMPONENT W OF THE RIDGE AXIS WILL DRAW MODEST AMOUNTS OF
MID-LEVEL MOISTURE INTO PARTS OF SRN NM WHERE DRY SFC CONDITIONS
WILL EXIST. MARGINAL BUOYANCY AND OROGRAPHIC EFFECTS MAY PROMOTE
ISOLATED HIGH-BASED THUNDERSTORM DEVELOPMENT ACROSS PARTS OF SRN NM.
THESE STORMS COULD CONTAIN LIMITED PRECIPITATION AMOUNTS OWING TO
RELATIVELY LOW PW AND DEEP SFC-BASED MIXED LAYERS SUPPORTING
SUB-CLOUD EVAPORATION. SOME RISK FOR DRY THUNDERSTORMS MAY EXIST.
HOWEVER...DEEP-LAYER FORCING FOR ASCENT IS NOT EXPECTED TO BE STRONG
ENOUGH TO SUPPORT ANY MORE THAN ISOLATED DRY THUNDERSTORMS. AS
SUCH...A DRY-THUNDERSTORM CRITICAL AREA IS NOT WARRANTED.
...COASTAL RANGES AND ADJACENT FOOTHILLS OF SRN CA FROM THE ERN
TWO-THIRDS OF SANTA BARBARA COUNTY EWD TO NWRN/N-CNTRL LOS ANGELES
COUNTY...
CRITICALLY LOW RH VALUES WILL CONTINUE FROM D1/WED INTO D2/THU AS A
DRY AIR MASS PERSISTS...WITH MINIMUM RH VALUES DURING THE AFTERNOON
ON D2/THU EXPECTED TO RANGE FROM THE UPPER SINGLE DIGITS TO THE
MIDDLE TEENS. POOR RH RECOVERY IS EXPECTED THU NIGHT. LOCALLY STRONG
NWLY TO NELY SFC WINDS WILL BE POSSIBLE THU MORNING...STRONGEST
THROUGH FAVORED PASSES AND CANYONS...AS THE PRESSURE GRADIENT WILL
INITIALLY BE TIGHT. HOWEVER...WIND SPEEDS ARE EXPECTED TO BE
DECREASING DURING THE DAY...AS THE BULK OF DETERMINISTIC MODEL
SOLUTIONS SUGGEST AN OVERALL SLACKENING OF THE SFC PRESSURE
GRADIENT. WHILE VERY DRY FUELS WILL COMBINE WITH THESE WINDS AND RH
VALUES TO SUPPORT ELEVATED TO PERHAPS BORDERLINE CRITICAL FIRE
WEATHER CONDITIONS...THE ANTICIPATED LOCALIZED/BRIEF NATURE OF ANY
STRONG-WIND THREAT PRECLUDES DESIGNATION OF A CRITICAL AREA AT THIS
TIME.
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...