Area Forecast Discussion
Issued by NWS Glasgow, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KGGW 241510
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
910 AM MDT SUN MAY 24 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
UPDATE...GOING FORECAST IN OVERALL EXCELLENT SHAPE. ONLY TWEAK WAS
TO DECREASE POPS AND SKY COVER ACROSS GARFIELD COUNTY AND THE BIG
SHEEP MOUNTAINS THIS MORNING GIVEN AN AREA OF CLEARING PUSHING
THROUGH. OTHERWISE THE GOING FORECAST STANDS. GILCHRIST

PREVIOUS DISCUSSION...UPPER LOW CURRENTLY OVER COLORADO AND UTAH
WILL DRIFT NORTH INTO WYOMING TODAY. FLOW OF MOISTURE AROUND THIS
LOW WILL MOVE NORTH INTO SOUTHERN MONTANA TODAY AND BRING A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS TO AREAS MAINLY SOUTH OF THE
MISSOURI RIVER. DRY AIR MASS AND WEAK HIGH PRESSURE TO THE NORTH
WILL KEEP THE NORTHERN ZONES MAINLY DRY TODAY ALTHOUGH THERE WILL
BE ENOUGH INSTABILITY THAT A THUNDERSTORM IS POSSIBLE THIS
AFTERNOON. ALSO... THICKER CLOUD COVER WILL KEEP THE SOUTHERN
ZONES COOLER THAN THE NORTHERN ZONES TODAY.

THE UPPER LOW WILL WEAKEN INTO AN OPEN TROUGH TONIGHT OVER WYOMING
BECOMES A VERY WEAK SYSTEM BY THE TIME IT MOVES INTO THE DAKOTA ON
MONDAY. MODEL DIFFER ON HOW FAR NORTH THE MOISTURE WILL PENETRATE
INTO EASTERN MONTANA AND NORTH DAKOTA TONIGHT AND MONDAY. MOST OF
THEM KEEP THE NW PART OF THE FORECAST AREA DRY AND BRING THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE SOUTHEAST ZONES. WILL
LIMIT POPS IN THE NORTHWEST TO A SLIGHT CHANCE OF THUNDERSTORMS
MONDAY AFTERNOON AND FOCUS THE HIGHEST POPS IN THE SOUTHEAST.

A WEAK SHORTWAVE COULD BRING A FEW SHOWERS AND THUNDERSTORMS TO
THE AREA MONDAY NIGHT AND A WEAK RIDGE MAY KEEP THE AREA DRY FOR
PARTS OR MOST OF TUESDAY BUT SOMEWHAT UNSTABLE AIR MASS WILL BE
FAVORABLE FOR SOME SHOWERS AND THUNDERSTORMS AT TIMES. FORRESTER

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
THERE IS FAIRLY DECENT 00Z MODEL AGREEMENT IN THE EXTENDED PERIOD
WHICH BEGINS TUESDAY NIGHT WITH AN UPPER TROUGH...WHICH WILL
GRADUALLY TRANSLATE EAST ACROSS THE NORTHERN HIGH PLAINS THROUGH
THE MIDWEEK. THIS TROUGH WILL MAINTAIN UPPER FORCING FOR ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD.

A SURFACE COLD FRONT LOOKS TO PUSH THROUGH THE REGION SOMETIME ON
THURSDAY. THE 00Z GFS AND ECMWF KEEP BEST CHANCES FOR SHOWER
ACTIVITY ON THE PERIPHERY OF THE CWA...BUT GIVEN THAT IT IS DAY 5
AND THE POTENTIAL FOR SOME ENHANCED SURFACE CONVERGENCE ALONG THE
COLD FRONT...WILL KEEP AT LEAST A SLIGHT CHANCE IN CENTRAL ZONES
FOR NOW.

WILL TREND TOWARD A DRY FORECAST FOR THE WEEKEND AS COMPARED WITH
PREVIOUS FORECASTS. LATEST GUIDANCE NOW SHOWS MORE AGREEABLE
SUPPORT FOR AN UPPER RIDGE BUILDING ACROSS THE WESTERN CONUS. THIS
WILL INEVITABLY LEAD TO RISING 1000-500 MB THICKNESSES ACROSS THE
AREA AND THUS WARMER TEMPERATURES. THE 00Z ECMWF 850MB
TEMPERATURES LOOK TO RANGE NEAR +20C OVER THE CWA BY 01 JUNE.
WHILE IT IS VERY PRELIMINARY THINKING...EARLY INDICATIONS ARE THAT
JUNE MAY START OUT ON A WARMER NOTE. WILL SEE IF FUTURE MODEL RUNS
OFFER SIMILAR SOLUTIONS...WHICH WOULD HELP TO BUILD CONFIDENCE.
FOR NOW WILL KEEP A DRY FORECAST AND WARMER TEMPERATURES TO FINISH
OUT THE EXTENDED PERIOD. MALIAWCO

&&

.AVIATION...
EXPECT VFR CONDITIONS ACROSS ALL TERMINALS EARLY THIS MORNING.
EVENTUALLY ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
BEGIN SPREADING NORTH...MOST LIKELY TO AFFECT KGDV AND KSDY. THE
SHOWER ACTIVITY MAY BE ACCOMPANIED BY MVFR CIGS AS WELL AS WELL AS
BRIEF RESTRICTIONS IN VISIBILITY. EAST WINDS WILL PERSIST AT 10 TO
15 KTS THROUGH THE DAY. MALIAWCO

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.