Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 290959
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
359 AM MDT WED JUL 29 2015

.SYNOPSIS...STRONG HIGH PRESSURE WILL PREVAIL TODAY THROUGH EARLY
THURSDAY. MOISTURE WILL BEGIN TO RETURN TO SOUTHERN UTAH LATE
THURSDAY AND THEN SPREAD SLOWLY NORTH OVER THE WEEKEND AS THE HIGH
SETTLES IN OVER NEW MEXICO AND OUR FLOW ALOFT TURNS SOUTHERLY.

&&

.SHORT TERM (THROUGH 00Z SATURDAY)...HIGH PRESSURE WILL CONTINUE
TO BUILD ACROSS THE REGION THROUGH THE SHORT TERM PORTION OF THE
FORECAST. SIGNIFICANT WARM AIR ADVECTION WILL BRING A SIGNIFICANT
CHANGE IN TEMPERATURES ACROSS THE NORTHERN VALLEYS. 700MB
TEMPERATURES NEAR 9C THIS MORNING ARE EXPECTED TO REACH 14C BY
THURSDAY EVENING. WHILE MAX TEMPERATURES ARE FORECAST TO AVERAGE
BETWEEN 5 TO 10 DEGREES BELOW NORMAL TODAY...EXPECT TEMPERATURES
NEAR NORMAL BY THURSDAY.

AS THE RIDGE BUILDS WESTWARD...MOISTURE WILL START TO INCREASE
ACROSS THE FAR SOUTH...STARTING THURSDAY AFTERNOON. MOST MODEL
GUIDANCE INDICATES THE DEPTH OF THIS MOISTURE WILL BE LIMITED...MORE
THAN LIKELY INDICATING THE BIGGEST THREAT WITH ANY CONVECTION WILL
BE MICROBURST WINDS RATHER THAN HEAVY RAIN. THE DEPTH OF THE
MOISTURE AND DEGREE OF INSTABILITY IMPROVE A BIT FRIDAY...BUT STILL
EXPECT THE LOW LEVELS WILL REMAIN DRY ENOUGH TO HEAD OFF MUCH OF A
HEAVY RAIN THREAT.

.LONG TERM (AFTER 00Z SATURDAY)...ALTHOUGH PWS CONTINUE TO
INCREASE AND SPREAD NORTHWARD SATURDAY THE RIDGE AXIS AT MID
LEVELS REMAINS STRETCHED ACROSS THE CWA FROM SOUTHEAST TO
NORTHWEST. THIS SHOULD KEEP A DRY NORTHWEST FLOW IN PLACE INTO
SUNDAY ACROSS THE WASATCH MOUNTAINS AND FRONT AS WELL AS SOUTHWEST
WYOMING. HAVE BACKED OFF ON THE POPS FOR SATURDAY AND SUNDAY IN
THESE AREAS AS MOISTURE NOT SHOWING UP BELOW 500 MB AND LIFTED
INDICES REMAINING POSITIVE AS WELL. LEFT JUST A SLIGHT CHANCE IN
THE UINTAS FOR SUNDAY BUT NOT VERY CONFIDENT THAT ANYTHING WILL
EVEN HAPPEN THERE. FARTHER SOUTH ACROSS THE SOUTHERN THIRD OF THE
CWA THE PWS COME UP OVER 0.75 OF AN INCH AND LIFTED INDICES LOWER
BELOW 1. HOWEVER...BECAUSE THE RIDGE IS STILL QUITE STRONG WITH
LITTLE EVIDENCE OF ANY DISTURBANCES TO HELP INITIATE CONVECTION THE
CURRENT FORECAST OF MINIMAL POPS LOOKS REASONABLE. THE LOWER
LEVELS ARE STILL FORECAST TO BE QUITE DRY SO THERE MAY BE MORE DRY
THUNDERSTORMS...ESPECIALLY OVER THE VALLEYS THEN ANY THREAT OF
RAIN.

THE RIDGE AXIS MOVES NORTHEAST INTO WYOMING MONDAY AND TUESDAY
WHICH WILL ALLOW MOISTURE TO SPREAD ACROSS THE ENTIRE CWA BUT ONCE
AGAIN NOT IMPRESSED WITH THE DEPTH OF THE MOISTURE AS TIME HEIGHTS
SHOWING MOST MOISTURE CONTRIBUTING TO THE HIGHER PWS IS AT HIGH
LEVELS AND NOT AT THE SURFACE. THEREFORE KEEPING THE POPS RATHER
LOW DURING THIS PERIOD WELL JUSTIFIED. HAVE DECREASED POPS FOR
WEDNESDAY AS A DRIER SOUTHWEST FLOW DEVELOPS.

TEMPERATURES WILL LIKELY BE ABOVE AVERAGE DURING THIS TIME AS H7
VALUES ARE EXPECTED TO BE AT +16 DEGREES CELSIUS OR HIGHER ACROSS
MOST OF THE CWA FROM SATURDAY THROUGH WEDNESDAY. THE ONLY FACTOR
THEY MAY INHIBIT TEMPERATURES FROM REACHING THEIR POTENTIAL WILL
BE CLOUD COVER OR SHOWERS.

&&

.FIRE WEATHER...HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE
REGION THROUGH THE WEEKEND. THIS WILL BRING A WARMING TREND TO MOST
OF THE DISTRICT...WITH TEMPERATURES NEAR TO ABOVE NORMAL LEVELS BY
THE WEEKEND. MOISTURE WILL GRADUALLY INCREASE ACROSS THE FAR SOUTH
THURSDAY...SLOWLY BUILDING NORTHWARD THROUGH THE WEEKEND. THIS
MOISTURE IS EXPECTED TO REMAIN SOMEWHAT LIMITED...WHICH MAY PROMOTE
THE THREAT OF DRY THUNDERSTORMS THURSDAY ACROSS THE SOUTHERN
MOUNTAINS...AND ACROSS MUCH OF SOUTHERN UTAH FRIDAY. THIS THREAT
WILL ENTIRELY DEPEND ON THE DEPTH OF THE MOISTURE SURGE AND IS
SOMETHING THAT WILL NEED TO BE MONITORED.

&&

.AVIATION...WINDS AT THE SLC TERMINAL ARE EXPECTED TO REMAIN LIGHT
AND SOMEWHAT VARIABLE THROUGH ABOUT 16Z. EXPECT THE NORTHERLY
GRADIENT TO SUPPORT THE DEVELOPMENT OF NORTHERLY WINDS ONCE MORE
AFTER 17Z.

&&

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

$$

STRUTHWOLF/KRUSE

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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