Storm Prediction Center Day 1 Fire Weather Outlook
Created: Mon Jun 16 16:59:04 UTC 2014 (
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Storm Prediction Center Day 1 Fire Weather Outlook
Created: Mon Jun 16 16:59:04 UTC 2014 (
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Click for Day 1 FireWX Areal Outline Product
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 161658
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1158 AM CDT MON JUN 16 2014
VALID 161700Z - 171200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NRN AZ...SRN
UT...NWRN NM...SWRN CO...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF INTERIOR/ERN CA...SRN
NV...SRN UT...SWRN CO...NRN HALF OF NM...NRN HALF OF AZ SURROUNDING
THE EXTREMELY CRITICAL AREA...
...PRIMARY CHANGES TO THE DAY-1 FIRE WEATHER OUTLOOK...
/1/ AN EXTREMELY CRITICAL AREA HAS BEEN ADDED ACROSS PORTIONS OF NRN
AZ...SRN UT...NWRN NM...AND SWRN CO...UPON COLLABORATION WITH THE
FLAGSTAFF...ALBUQUERQUE...LAS VEGAS...SALT LAKE CITY...AND GRAND
JUNCTION WEATHER FORECAST OFFICES. THE MORNING OBSERVED SOUNDING AT
FLAGSTAFF INDICATES 45-55 MPH OF FLOW EXTENDING AS LOW AS 3 KFT
ABOVE GROUND...AND FLAGSTAFF VWP INDICATES OVER-40-MPH SWLYS BETWEEN
1.5 AND 3 KFT AGL. THIS IS IN ASSOCIATION WITH A BAND OF STRONG
MID-LEVEL FLOW THAT WILL BE MAINTAINED THROUGH THE DAY AS A TROUGH
DIGS OVER THE WRN STATES. FURTHERMORE...A VERY DRY TROPOSPHERE IS IN
PLACE...AS HIGHLIGHTED BY THE FLAGSTAFF SOUNDING INDICATING 0.1-INCH
PW...AND GPS DATA INDICATING PW OF 0.1-0.3 INCH ACROSS MUCH OF THE
REGION.
AS DIURNAL MIXING IS ENHANCED...THE AFOREMENTIONED FACTORS WILL
SUPPORT SWLY SFC WINDS OF 30-35 MPH WITH GUSTS LOCALLY REACHING
AROUND 50 MPH ALONG WITH MINIMUM RH OF 3-9 PERCENT ACROSS THE
EXTREMELY CRITICAL AREA. THESE ANTICIPATED PARAMETERS ARE ALSO
SUBSTANTIATED BY THE LATEST CONSENSUS AMONGST SHORT-RANGE
DETERMINISTIC/ENSEMBLE MODEL GUIDANCE...INCLUDING THE LATEST
RAP...SREF...EXPERIMENTAL SSEO...AND EXPERIMENTAL 4-KM AFWA ENSEMBLE
OUTPUT...WHICH ALL HIGHLIGHT VERY STRONG WINDS AND VERY LOW RH.
FURTHERMORE...SFC OBSERVATIONS ALREADY INDICATE WINDS HAVING BECOME
STRONG THIS MORNING ACROSS THE REGION WITH RH VALUES OF 8-15
PERCENT...AND FURTHER REDUCTIONS IN RH AND INCREASES IN WIND SPEEDS
ARE EXPECTED WITH STRENGTHENING MIXING AND A TIGHTENING SFC PRESSURE
GRADIENT.
WITH ALL OF THESE FACTORS COMBINED AMIDST VERY DRY FUELS...THE
UPGRADE TO EXTREMELY CRITICAL DESIGNATION IS NECESSARY. ONGOING
FIRES WILL HAVE THE POTENTIAL TO SPREAD VERY RAPIDLY OWING TO THE
AFOREMENTIONED CONDITIONS.
/2/ THE CRITICAL AREA HAS BEEN EXTENDED EWD ACROSS PORTIONS OF THE
NRN HALF OF NM WHERE 20-25 MPH WINDS ARE FORECAST TO COMBINE WITH RH
OF 10-15 PERCENT PER THE LATEST OBSERVATIONAL TRENDS/MODEL OUTPUT.
COORDINATION WITH THE ALBUQUERQUE WEATHER FORECAST OFFICE SUGGESTS
FUELS ARE DRY ACROSS AREAS ADDED TO CRITICAL DESIGNATION. GREEN-UP
OF FUELS IN NERN NM PRECLUDES CRITICAL DESIGNATION THERE...DESPITE
METEOROLOGICALLY CRITICAL FIRE WEATHER CONDITIONS.
/3/ THE CRITICAL AREA HAS BEEN EXTENDED WWD INTO ADDITIONAL PORTIONS
OF SRN NV AND ACROSS INTERIOR/ERN CA TO THE SRN SIERRA WHERE VERY
DRY FUELS EXIST AMIDST EXPECTED 20-25 MPH WINDS AND MINIMUM RH OF
10-15 PERCENT PER THE LATEST MODEL GUIDANCE. OBSERVATIONS INDICATE
STRONG WINDS/LOW RH ALREADY IN PLACE...AND THESE CONDITIONS WILL BE
REINFORCED WITH STRONG 700-MB FLOW OVERLYING THE AREA DURING PEAK
HEATING.
/4/ THE ELEVATED FIRE WEATHER AREA HAS BEEN EXTENDED SWD TO THE
UNITED-STATES/MEXICO BORDER...WITH AREAS ADDED TO ELEVATED
DESIGNATION EXPECTED TO EXPERIENCE 15-20 MPH WINDS AMIDST RH AROUND
10-15 PERCENT. THESE LOCATIONS WILL REMAIN DISPLACED TO THE S OF
STRONGER FLOW ALOFT...PRECLUDING CRITICAL DESIGNATION AT THIS TIME.
/5/ AN ISOLATED DRY-THUNDERSTORM AREA HAS BEEN ADDED ACROSS PORTIONS
OF SERN AZ...SRN NM...AND THE TRANS-PECOS REGION OF TX. WITH GPS PW
AROUND 0.50-0.75 INCH ACROSS THIS AREA OWING TO AN INFLUX OF MODEST
MID-LEVEL MOISTURE...MARGINAL BUOYANCY WILL MATERIALIZE THIS
AFTERNOON. WHEN COMBINED WITH OROGRAPHIC CIRCULATIONS...ISOLATED
THUNDERSTORM DEVELOPMENT IS EXPECTED. A DRY THUNDERSTORM MODE WILL
BE FAVORED BY DEEP INVERTED-VEE THERMODYNAMIC PROFILES PER FORECAST
SOUNDINGS...ALONG WITH MODERATE STORM MOTIONS OWING TO 20-35 MPH OF
FLOW THROUGH THE CLOUD LAYER. THE LACK OF STRONGER DEEP ASCENT
SHOULD PREVENT GREATER DRY THUNDERSTORM COVERAGE FROM ENSUING.
..COHEN.. 06/16/2014
.PREV DISCUSSION... /ISSUED 0400 AM CDT MON JUN 16 2014/
...SYNOPSIS...
PACIFIC NORTHWEST MID-/UPPER-LEVEL TROUGH SHOULD CONTINUE TO SLOWLY
DIG SOUTHWARD TOWARD THE NORTHERN GREAT BASIN. AS THIS
OCCURS...STRONG MID-/UPPER-LEVEL FLOW WILL OVERSPREAD MUCH OF THE
GREAT BASIN AND SOUTHWEST UNITED STATES. DOWNSTREAM...A DEPARTING
SHORT-WAVE TROUGH WILL CONTINUE TO LIFT NORTHWARD INTO WESTERN
ONTARIO LEAVING SOUTHWEST FLOW IN ITS WAKE ACROSS MUCH OF THE UNITED
STATES. THE EXCEPTION BEING THE SOUTHEAST WHICH WILL BE UNDER THE
INFLUENCE OF A SUBTROPICAL RIDGE AND THE NORTHEAST WHERE THE FLOW
WILL BE MORE WESTERLY.
AT THE SURFACE...MUCH OF THE EAST WILL BE UNDER THE INFLUENCE OF A
LARGE HIGH PRESSURE AREA CENTERED OFF THE COAST OF NORTH CAROLINA.
ACROSS THE WEST...AN EXPANSIVE AREA OF LOWER PRESSURE WILL
PERSIST...WITH SEVERAL EMBEDDED MINIMA. IN BETWEEN...A LEE TROUGH
WILL PERSIST ACROSS THE HIGH PLAINS...WITH AN EMBEDDED SURFACE LOW
DEVELOPING SOUTHWARD FROM EASTERN MONTANA INTO NORTHEAST COLORADO.
...SOUTHEASTERN CALIFORNIA...FAR SOUTHERN NEVADA...NORTHERN
ARIZONA...SOUTHERN UTAH...FAR WEST/SOUTHWESTERN
COLORADO...NORTHWESTERN NEW MEXICO...
STRONG INSOLATION WILL ONCE AGAIN PROMOTE THE DEVELOPMENT OF A
DEEP...WELL-MIXED BOUNDARY LAYER...WHICH WILL YIELD MINIMUM SURFACE
RELATIVE-HUMIDITY VALUES BETWEEN 5 AND 15 PERCENT. COUPLED WITH
THIS...AN INCREASING SURFACE PRESSURE GRADIENT WILL ALLOW FOR AN
INCREASE IN SUSTAINED SURFACE WIND SPEEDS...WITH EVEN STRONGER GUSTS
RESULTING FROM INCREASING FLOW ALOFT BEING MIXED DOWN TO THE
SURFACE.
AT THIS TIME...THE CORRIDOR FROM EASTERN CALIFORNIA EASTWARD ACROSS
SOUTHERN NEVADA/NORTHERN ARIZONA/SOUTHERN UTAH INTO SOUTHWESTERN
COLORADO AND NORTHWEST NEW MEXICO IS EXPECTED TO HAVE
RELATIVE-HUMIDITY VALUES FALL INTO THE SINGLE DIGITS WITH SUSTAINED
SURFACE WINDS SPEEDS GREATER THAN 20 MPH /WITH GUSTS LOCALLY
REACHING 40+ MPH/. THIS WILL RESULT IN WIDESPREAD CRITICAL
FIRE-WEATHER CONDITIONS.
THE POTENTIAL EXISTS FOR A SUBSET OF THIS CORRIDOR TO ACHIEVE
EXTREMELY CRITICAL CONDITIONS. NUMERICAL GUIDANCE SUPPORTS THE
DEVELOPMENT OF AN AREA OF SUSTAINED SURFACE WIND SPEEDS APPROACHING
/OR EVEN EXCEEDING/ 30 MPH /WITH GUSTS NEARING 50 MPH/. AT THIS TIME
THE MOST LIKELY AREA WHERE THIS WOULD OCCUR IS NORTH-CENTRAL
ARIZONA. HOWEVER...ENOUGH UNCERTAINTY REMAINS IN THE EXACT LOCATION
AND DURATION OF THIS HIGHER-END THREAT TO PRECLUDE EXTREMELY
CRITICAL DELINEATION AT THIS TIME.
...AREAS SURROUNDING THE CRITICAL RISK...
AFTERNOON RELATIVE-HUMIDITY VALUES ARE EXPECTED TO FALL BELOW 25
PERCENT ACROSS MUCH OF THE AREA. ADDITIONALLY...SUSTAINED SURFACE
WINDS AROUND 15-25 MPH ARE EXPECTED. HOWEVER...UNLIKE THE
CRITICAL-RISK AREA...THE PHASING OF STRONGEST SURFACE WINDS...LOWEST
RELATIVE-HUMIDITY VALUES...AND/OR DRY FUELS WILL NOT SUFFICIENTLY
OCCUR TO SUPPORT LARGE-SCALE FIRE-WEATHER CONDITIONS.
HOWEVER...ELEVATED TO LOCALLY CRITICAL FIRE-WEATHER CONCERNS WILL
REMAIN.
...HIGHER TERRAIN OF SOUTHEAST ARIZONA AND SOUTHWEST/WEST-CENTRAL
NEW MEXICO...
FORECAST SOUNDINGS ACROSS THIS AREA INDICATE THE DEVELOPMENT OF
MODEST INSTABILITY /MUCAPE VALUES AROUND 500 J/KG/ DEVELOPING ATOP A
VERY DEEP BOUNDARY LAYER BY EARLY AFTERNOON. OROGRAPHIC
CIRCULATIONS...COUPLED WITH AN INCREASE IN PRECIPITABLE-WATER VALUES
TO AROUND 0.8 INCHES...MAY SUPPORT THE DEVELOPMENT OF ISOLATED
THUNDERSTORMS. THIS AREA IS ON THE SOUTHERN FRINGES OF THE STRONGER
MID-/UPPER-LEVEL FLOW AND THUS STORM MOTIONS MAY BE FAST ENOUGH TO
OFFSET THE INCREASE IN PRECIPITABLE WATER TO KEEP AT LEAST SOME
POTENTIAL FOR DRY THUNDERSTORMS. HOWEVER...CONCERNS REGARDING
THUNDERSTORM COVERAGE AND THE HIGHER PRECIPITABLE-WATER VALUES WILL
PRECLUDE DRY THUNDERSTORM HIGHLIGHTS AT THIS TIME. IF COVERAGE OF
THUNDERSTORMS IS GREATER THAN...OR PRECIPITABLE-WATER VALUES LOWER
THAN FORECAST...INTRODUCTION OF AN ISOLATED DRY-THUNDERSTORM AREA
MAY BE REQUIRED WITH THE DAY-1 UPDATE.
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...