Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 281723
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1123 AM MDT THU MAY 28 2015

.SYNOPSIS...AN UPPER LOW OVER THE NORTHERN ROCKIES WILL MOVE EAST
INTO THE PLAINS STATES BY FRIDAY. HIGH PRESSURE WILL STRENGTHEN
ACROSS THE REGION THIS WEEKEND...RESULTING IN A SUBSTANTIAL
WARMING AND DRYING TREND.

&&

.DISCUSSION...A SLOW MOVING TROUGH WILL CROSS IDAHO INTO WYOMING
TODAY. AHEAD OF THIS TROUGH...SUFFICIENT DYNAMIC LIFT SHOULD
OCCUR ACROSS MUCH OF THE CWA SUPPORTING FAIRLY WIDESPREAD
CONVECTION.

THE MAIN QUESTION IS TO HOW ORGANIZED THIS CONVECTION WILL BE
THROUGH THE AFTERNOON AND EVENING. SREF ENSEMBLE DATA INDICATES
THE MAIN STUMBLING POINT WILL BE THE AMOUNT OF INSTABILITYAVAILABLE...AS
MUCAPE VALUES REMAIN AT OR BELOW 500 J/KG ACROSS MUCH OF CENTRAL
AND SOUTHERN UTAH.

THE CWA WILL NOT BE LACKING FOR DEEP LAYER SHEAR. MORNING
MESOANALYSIS INDICATES 0-6KM BULK SHEAR VALUES NEARING 45-50KTS
ACROSS MUCH OF THE STATE OF UTAH. EXPECT WITH THIS AMOUNT OF DEEP
LAYER SHEAR THAT LACK OF INSTABILITY MAY BE OVERCOME. THE HRRR HAS
BEEN QUITE INSISTENT WITH TWO FOCUSES OF CONVECTION THIS
AFTERNOON/EVENING...ALONG THE UTAH/IDAHO BORDER THROUGH UINTA
COUNTY WYOMING AND ACROSS THE SOUTHERN HALF OF UTAH. THIS MATCHES
WITH WHAT ONE WOULD EXPECT BASED ON SUBJECTIVE ANALYSIS.

LOOKING AT THE 12Z SLC SOUNDING...EXPECT THE THREAT OF STRONG
WINDS IS LOWER THAN NORMAL GIVEN HOW MOIST THE ENVIRONMENT
REMAINS. THE MAIN THREATS WITH ANY ORGANIZED STORMS WILL BE HAIL
AND HEAVY RAIN. EVEN WITH THE RELATIVELY MOIST ENVIRONMENT...GUSTY
WINDS ARE ALWAYS A THREAT...PARTICULARLY WITH COLLAPSING STORMS.

UPDATED THE FORECAST TO MAINLY TO INCREASE POPS ACROSS THE SOUTH
AFTER 00Z. NO ADDITIONAL UPDATES ARE ANTICIPATED AT THIS TIME.

SALT LAKE CITY AIRPORT BROKE THE RECORD FOR NUMBER OF DAYS WITH
MEASURABLE PRECIPITATION FOR THE MONTH OF MAY. THIS MONTH IS ALSO
RANKED FIFTH FOR THE NUMBER OF DAYS OF MEASURABLE PRECIPITATION
FOR ANY MONTH SINCE 1874.

&&

.AVIATION...SOUTHEAST WINDS AT THE SLC TERMINAL ARE EXPECTED
TO SWITCH TO NORTHWEST BETWEEN 17-19Z. OPERATIONAL WEATHER CONCERNS
WILL FOCUS ON PERIODIC SHOWERS AFTER ABOUT 19Z...WITH A 20 PERCENT
CHANCE OF THUNDERSTORMS THROUGH 23Z. PRIMARY IMPACTS FROM PASSING
SHOWERS/STORMS WILL BE A BRIEF REDUCTION OF CIGS TO AOB 6000FT
AGL...GUSTY ERRATIC WINDS AND LIGHTNING IN THE VICINITY OF THE
AIRFIELD.

&&

.FIRE WEATHER...EXPECTING FAIRLY SIMILAR TEMPERATURE/HUMIDITY TODAY
COMPARED TO YESTERDAY. IT WILL ONCE AGAIN BE SOMEWHAT COOL/MOIST
ACROSS THE NORTH...AND DRY AND WARM ACROSS THE SOUTH. AFTERNOON AND
EVENING THUNDERSTORMS HOWEVER SHOULD BE MORE EVENLY DISTRIBUTED
ACROSS THE STATE. THE STRONGEST ACTIVITY WILL BRING A CHANCE FOR
CLOUD TO GROUND LIGHTNING...BRIEF HEAVY RAIN...SMALL
HAIL...AND GUSTY/ERRATIC WINDS.

THE PATTERN SHIFTS TOMORROW THROUGH THE WEEKEND AS A RIDGE BUILDS
IN. EXPECT VERY WARM CONDITIONS AND A DRYING TREND ACROSS ALL OF
UTAH. THE CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS WILL THIN
EACH DAY AND BE RELEGATED TO THE MOUNTAINS FOR THE MOST PART.
SOUTHERLY WINDS WILL BECOME GUSTY SUNDAY...INCREASING THROUGH
TUESDAY...WITH A STRONG LIKELIHOOD OF SEEING CRITICAL METEOROLOGICAL
FIRE WEATHER CONDITIONS SUNDAY INTO EARLY NEXT WEEK.

COOLING AND MOISTENING CONDITIONS DEVELOP ACROSS THE NORTH BY MID
WEEK BEHIND THE NEXT COOL FRONT. SHOWERS SHOULD INCREASE IN COVERAGE
AGAIN YET SHOULD NOT BE AS WIDESPREAD AS THE LAST COUPLE OF WEEKS.


&&

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

$$

KRUSE/SCHOENING/VERZELLA/ROGOWSKI

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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