Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 242145
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
245 PM MST TUE FEB 24 2015

.SYNOPSIS...HIGH PRESSURE WILL RETURN TO THE AREA TONIGHT...FOLLOWED
BY A COUPLE OF WEAK WEATHER DISTURBANCES CROSSING THE REGION
TONIGHT THROUGH FRIDAY. A COLDER STORM SYSTEM MAY AFFECT PARTS OF
THE REGION THIS UPCOMING WEEKEND.

&&

.SHORT TERM (THROUGH 12Z FRIDAY)...
WATER VAPOR LOOP SHOWS A CLOSED LOW OVER NORTHERN ARIZONA. AMDAR
400- 250MB WIND OBSERVATIONS INDICATE A WESTERLY 125-160KT JET
ACROSS FAR SOUTHERN CALIFORNIA INTO THE FOUR CORNERS.
GOES/GPS/RAP/12Z RAOB INDICATE THE PRECIPITABLE WATER VALUE RANGES
BETWEEN 0.05-0.10" CENTRAL UTAH...TO 0.30-0.40" FAR SOUTH. BLENDED
TOTAL PRECIPITABLE WATER PRODUCT INDICATES ABNORMALLY DRY AIRMASS
OVER THE GREAT BASIN AND ABNORMALLY MOIST AIRMASS ACROSS THE FAR
NORTHERN ROCKIES.

IN THE NEAR TURN FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FOG IN
THE WAKE OF THE STORM. SINCE WE ARE IN A NEW REGIME...HAVE TAKEN A
FEW DEGREES OFF OF BIAS CORRECTED GUIDANCE ACROSS THE REGION.
CLEARING SKIES AND A DEEP SNOWPACK SHOULD SUPPORT TEMPERATURES WELL
BELOW GUIDANCE FOR THE NEXT SEVERAL DAYS ACROSS SOUTHERN UTAH. THERE
MAY BE SUPPORT FOR FOG LATER TONIGHT AND TOMORROW MORNING GIVEN
DROPPING TEMPERATURES AIDED BY CLEAR SKIES AND A FRESH SNOWPACK WITH
SOME DAYTIME MELTING. BACKED OFF ON FOG WORDING A BIT AS DEWPOINT
HAVE REALLY COME DOWN ALONG THE INTERSTATE 15 CORRIDOR.

FIRST DISTURBANCE PASSES OVER THE ROCKIES TOMORROW. WITH A DRY
STABLE AIRMASS IN PLACE NOT CONCERNED ABOUT MUCH PRECIPITATION.
SHORT RANGE ENSEMBLES DO SHOW SOME AFTERNOON INSTABILITY SO KEPT
MENTION OF SNOW SHOWERS FOR NORTHEAST ZONES. BIGGER CONTRIBUTION
FROM THIS SYSTEM WILL LIKELY BE TO KICK UP DOWNSLOPE WINDS ACROSS
FAVORED AREAS OF FAR NORTHWEST UTAH...AND EAST CENTRAL/SOUTHERN
UTAH...ALONG WITH SOME PASSING MID AND HIGH CLOUDS.

LARGE SCALE PATTERN BEGINS TO RELOAD THE WESTERN TROUGH BEGINNING
THURSDAY. WITH ARRIVAL OF THE NOSE OF THE JET AND SOME
INSTABILITY...COULD SEE ISOLATED TO SCATTERED SHOWERS SPREAD ACROSS
NORTHERN TWO THIRDS OF UTAH AND SOUTHWEST WYOMING...THOUGH IMPACT
SHOULD BE MINIMAL THROUGH THURSDAY NIGHT.

&&

.LONG TERM (AFTER 12Z FRIDAY)...
A POSITIVELY TILTED UPPER TROUGH IS FORECAST TO DEVELOP ACROSS
THE GREAT BASIN LATE IN THE WEEK...EVENTUALLY EVOLVING INTO AN
UPPER LOW AND LINGER ACROSS THE REGION THROUGH THE WEEKEND. THE
MEDIUM RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT AT THIS POINT
WITH RESPECT TO THE OVERALL EVOLUTION OF THIS TROUGH...WHICH IS
EXPECTED TO DEVELOP IN A SIMILAR FASHION TO THE TROUGH OF THIS
PAST WEEKEND WHICH WILL AGAIN FAVOR SOUTHERN UT. PREVIOUS FORECAST
INCREASED POPS QUITE A BIT ACROSS THE SOUTHERN HALF OF THE STATE
AND LOOKS REPRESENTATIVE...THUS ONLY MADE MINOR TWEAKS TO SLOW
DOWN THE ONSET OF PRECIP A BIT ON FRIDAY. THE LARGE SCALE PATTERN
IS FORECAST TO REMAIN ACTIVE THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...WITH ANOTHER UPPER TROUGH QUICKLY DIGGING INTO THE GREAT
BASIN LATE MONDAY INTO TUESDAY.

&&

.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH THE TAF PERIOD AT
KSLC...WITH NORTHWESTERLY SURFACE WINDS RETURNING TO THE SOUTH
DURING THE 03-05Z TIMEFRAME.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&

$$

SHORT TERM...ROGOWSKI
LONG TERM/AVIATION...SEAMAN

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)

FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)



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