Fire Weather Outlook Discussion
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FNUS22 KWNS 241716
FWDDY2

DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1216 PM CDT SAT SEP 24 2016

VALID 251200Z - 261200Z

...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA...

...PORTIONS OF SOUTHERN CALIFORNIA...
SCENARIO OUTLINED IN THE PREVIOUS FORECAST /DISCUSSION BELOW/
REMAINS VALID AND NO CHANGES WERE NEEDED TO THE PREVIOUS FORECAST.
THE TIGHTEST PRESSURE GRADIENT AND RESULTING STRONGEST WINDS ARE
ANTICIPATED AT THE BEGINNING AND END OF THE PERIOD - I.E. AROUND 12Z
SUN AND AGAIN AROUND 12Z MON -- WITH THE TYPICAL DIURNAL REDUCTION
DURING THE DAY. HOWEVER...BETTER UPPER SUPPORT IS ANTICIPATED
SUNDAY...LIKELY HELPING TO KEEP WINDS GUSTY THROUGHOUT THE DAY.
WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED.

...PORTIONS OF THE NORTHERN CALIFORNIA...
ONLY CHANGE TO THE PREVIOUS OUTLOOK WAS TO INCLUDE MOST OF THE
SACRAMENTO VALLEY IN AN ELEVATED DELINEATION WHERE WARM AND BREEZY
CONDITIONS ARE POSSIBLE DURING THE AFTERNOON. OTHERWISE...THE
PREVIOUS FORECAST REMAINS ON TRACK WITH ELEVATED TO LOCALLY CRITICAL
FIRE WEATHER CONDITIONS STILL ANTICIPATED ACROSS THE HIGHER
ELEVATIONS PARTICULARLY EARLY SUNDAY AND MONDAY MORNINGS.

...PORTIONS OF THE NRN/CNTRL PLAINS...
BREEZY NWLY WINDS ARE LIKELY WITHIN THE DRY...POST-FRONTAL AIRMASS
BUT RH VALUES ARE STILL EXPECTED TO REMAIN ABOVE 20 PERCENT.
ADDITIONALLY...THE OVERALL DURATION OF OVERLAPPING DRY AND WINDY
CONDITIONS WILL LIKELY BE LESS THAN 3 HOURS. THESE FACTORS WILL ACT
TO MITIGATE THE FIRE WEATHER POTENTIAL...PRECLUDING THE NEED FOR AN
ELEVATED DELINEATION WITH THIS FORECAST.

..MOSIER.. 09/24/2016

.PREV DISCUSSION... /ISSUED 0237 AM CDT SAT SEP 24 2016/

...SYNOPSIS...
THE MID/UPPER-LEVEL TROUGH ACROSS THE ROCKIES/HIGH PLAINS WILL
BECOME MORE SHEARED THROUGH THE PERIOD...AS AN EMBEDDED CLOSED
CYCLONE OVER THE NORTHERN PLAINS OPENS/LIFTS NORTHEAST INTO WESTERN
ONTARIO. MEANWHILE...ANOTHER CLOSED CYCLONE OVER THE SOUTHWEST WILL
DRIFT TOWARDS THE GULF OF CALIFORNIA. NORTH OF THIS LOW...RIDGING
WILL CONTINUE TO BUILD OVER THE GREAT BASIN AND NORTHERN ROCKIES.

...PORTIONS OF SOUTHERN CALIFORNIA...
CRITICAL FIRE-WEATHER CONCERNS WILL LIKELY BE ONGOING ACROSS MANY
LOCATIONS SUNDAY MORNING...AS FAVORABLE NORTHEASTERLY MID-LEVEL FLOW
ALIGNS WITH A MAXIMIZING SFC PRESSURE GRADIENT TO SUPPORT WIDESPREAD
OFFSHORE FLOW. SUSTAINED WINDS AROUND 20-30 MPH /WITH GUSTS UPWARDS
OF 45-55 MPH/ ARE LIKELY AT THE BEGINNING OF THE PERIOD. RH VALUES
SHOULD FALL RAPIDLY INTO THE TEENS THROUGH THE MORNING...WITH MIN
VALUES AROUND 5-15 PERCENT AS TEMPS CLIMB WELL INTO THE 90S IN MANY
LOCATIONS. WHILE WINDS MAY WEAKEN SOME THROUGH THE AFTERNOON...THE
MID-LEVEL LOW OVER NORTHWEST MEXICO WILL LIKELY MAINTAIN FAVORABLE
NORTHEASTERLY FLOW ALOFT OVER THE REGION...SUCH THAT BREEZY
NORTHEAST WINDS SHOULD PERSIST INTO THE LATE MORNING/EARLY AFTERNOON
WHEN RH VALUES PLUMMET. AS SUCH...CRITICAL CONCERNS ARE LIKELY TO
CONTINUE IN BOTH HIGHER ELEVATIONS AND SOME COASTAL LOCATIONS
THROUGH PART OF THE DAY.

NOCTURNAL ENHANCEMENT OF THE OFFSHORE PRESSURE GRADIENT SUNDAY NIGHT
WILL ENCOURAGE ANOTHER ROUND OF CRITICAL CONDITIONS...ESPECIALLY
ACROSS MOUNTAINS AND ADJACENT FOOTHILLS WHERE RH RECOVERY IS POOR.

...PORTIONS OF NORTHERN CALIFORNIA...
ELEVATED/LOCALLY CRITICAL CONCERNS WILL BE ONGOING AT THE BEGINNING
OF THE PERIOD...AS THE SFC PRESSURE GRADIENT ENCOURAGES EASTERLY
DOWNSLOPE WINDS SUSTAINED AROUND 15-25 MPH. POOR RH RECOVERY /WITH
VALUES AROUND 15-30 PERCENT IN THE MORNING/ WILL FURTHER ENHANCE THE
POTENTIAL FOR RAPID FIRE SPREAD. WHILE WINDS SHOULD WEAKEN THROUGH
THE DAY...ELEVATED CONCERNS ARE LIKELY TO PERSIST IN SOME SPOTS
THROUGH AT LEAST EARLY AFTERNOON.

...PORTIONS OF THE NORTHERN/CENTRAL PLAINS...
GUSTY POST-FRONTAL WINDS WILL POSITION OVER THE DAKOTAS AND NEBRASKA
ON SUNDAY...WITH SUSTAINED NORTHWEST WINDS AROUND 20-30 MPH
POSSIBLE. A DRY AIR MASS WILL SPREAD ACROSS THE REGION AS
WELL...WITH RH VALUES LIKELY FALLING TO AROUND 20-30 PERCENT. WHILE
THESE CONDITIONS ARE CONSISTENT WITH ELEVATED/LOCALLY CRITICAL
CONCERNS...THUNDERSTORMS ARE CURRENTLY ONGOING ACROSS MUCH OF THE
REGION. AS SUCH...FUEL RECEPTIVENESS REMAINS IN
QUESTION...PRECLUDING AN ELEVATED DESIGNATION AT THIS TIME.

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

$$


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