Flash Flood Warning 16, NWS Glasgow, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
920 PM MDT MON JUL 2 2007

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
ONGOING SEVERE WEATHER EVENT CONTINUES WITH A NUMBER OF LARGE HAIL
REPORTS AND A FEW 60 MPH WIND REPORTS AS WELL IN ADDITION TO FLASH
FLOODS. UPPER SHORTWAVE FROM THE WSW GENERATING THE SEVERE
WEATHER MUCH AS EXPECTED AS IT ENCOUNTERS THE MOIST AND UNSTABLE
AIRMASS OVER THE AREA. MAIN ACTIVITY HAS FOCUSED ALONG THE
INVERTED SURFACE TROUGH AND TIGHTEST DEW POINT GRADIENT ALONG AND
JUST AHEAD OF THE TROUGH. BEHIND THE TROUGH AND UPPER
SHORTWAVE...MUCH LESS ACTIVITY IN DRIER AND MORE STABLE AIRMASS.
EXPECT THE TSTORM ACTIVITY TO CONTINUE MOST OF THE NIGHT AS
AIRMASS TO REMAIN QUITE UNSTABLE IN OUR EAST. UPDATE MAINLY FOR
FINE-TUNING OF POPS. SIMONSEN

PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH
WEDNESDAY...ONE MORE ROUND OF THUNDERSTORMS TONIGHT...SOME LIKELY
SEVERE...TO BE FOLLOWED BY DRY WEATHER HEADING TOWARD THE 4TH OF
JULY.

TONIGHT...THE AREA REMAINS IN A MOIST AND HIGHLY UNSTABLE SOUTHWEST
FLOW ALOFT.  A STRONG SHORTWAVE THAT WAS IN CENTRAL OREGON THIS
MORNING IS NOW PUSHING THROUGH IDAHO AND INTO WESTERN MONTANA.  THIS
SHORTWAVE SHOULD BE THE TRIGGER FOR SCATTERED THUNDERSTORMS
TONIGHT.  SOME OF THESE STORMS WILL LIKELY TURN SEVERE.  EARLY ON
THE CELLS ARE LIKELY TO BE MORE DISCRETE WITH THE PRIMARY THREAT OF
LARGE HAIL.  AS THE LOW LEVEL JET KICKS IN LATER TONIGHT AND BEGINS
TO SHIFT EAST THE CONVECTION WILL LIKELY DEVELOP INTO AN MCS IN
EXTREME EASTERN MONTANA OR WESTERN NORTH DAKOTA.  AT THIS POINT THE
THREAT OF DAMAGING WIND WILL BE ON THE INCREASE...ALTHOUGH ANY
SUPERCELLS THIS EVENING WILL HAVE THE THREAT OF DAMAGING WIND
GUSTS.

A SPECIAL 18Z SOUNDING HAD A MODEST CAP AROUND 850MB.  CONTINUED
STRONG DAYTIME HEATING SHOULD EASILY ERODE THE CAP.  MODIFYING THE
SOUNDING FOR A HIGH IN THE UPPER 80S GIVES AN LI OF -8C AND ABOUT
2800 J/KG ABOVE THE LFC.  ALREADY HAVE SEEN SOME STORMS DEVELOP IN
SOUTHERN SASKATCHEWAN THAT HAVE QUICKLY TURNED STRONG TO SEVERE.
SHOULD BEGIN TO SEE MORE INITIATION ACROSS CENTRAL MONTANA DURING
THE NEXT COUPLE OF HOURS...AND THINGS ARE LOOKING PRIME FOR SEVERE
WEATHER JUST ABOUT ANYWHERE ACROSS THE CWA THIS EVENING...ALTHOUGH
IT MAY TAKE A LITTLE LONGER TO ERODE THE CAP ACROSS THE SOUTHEAST
ZONES.

TUESDAY...LINGERING CONVECTION POSSIBLE ACROSS THE EASTERN ZONES
THROUGH ABOUT MID-MORNING DEPENDING ON JUST WHERE THE MCS DEVELOPS
AND TRACKS TONIGHT.  IN THE WAKE OF THIS SYSTEM A STRONG RIDGE
BEGINS TO BUILD NORTH FROM AROUND LAS VEGAS WITH THE UPPER FLOW
BECOMING WEST/NORTHWEST.  THIS SHOULD DRY THINGS OUT AND STABILIZE
THE ATMOSPHERE...AND FINALLY PUT AN END TO WHAT HAS BEEN AN ACTIVE
PERIOD OF CONVECTION.  500MB HEIGHTS ARE EXPECTED TO BE WELL INTO
THE 580S (DAM) WITH 1000-500MB THICKNESS VALUES IN THE 570S (DAM)...
AND TEMPERATURES WILL CONTINUE TO BE ABOVE AVERAGE.

TUE NIGHT & WEDNESDAY...THE STRONG HOT/DRY RIDGE SLOWLY BUILDS
NORTH.  THIS WILL KEEP THE AREA FAIRLY STABLE AND DRY WITH ABOVE
AVERAGE TEMPERATURES.  OTHER THAN A FEW TWEAKS TO RAISE TEMPERATURES
A BIT AT A FEW OF THE NORMAL HOT SPOTS ACROSS THE WESTERN ZONES DID
NOT MAKE ANY CHANGES. CB

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
UPDATE...MODELS ARE MAINTAIN THE IDEA OF AN UPPER RIDGE OVER THE
AREA UNTIL SATURDAY. THIS WILL BRING HOT AND DRY WEATHER WITH IT.
RIDGE FLATTENS OVER THE WEEKEND WHICH SHOULD DELIVER A COLD FRONT
THAT THE MODELS ARE TIMING FOR LATE SATURDAY AT THIS POINT. ADDED
A SLIGHT CHANCE OF THUNDERSTORMS TO PART OF THE AREA FOR SUNDAY
AND SUNDAY NIGHT FOR A SHORTWAVE PASSING THROUGH. OTHERWISE...NO
SIGNIFICANT CHANGES TO THE FORECAST. FORRESTER

PREVIOUS LONG TERM...
GOOD MODEL AGREEMENT THROUGH FRIDAY WITH RIDGEBUILDING OVER THE
HIGH PLAINS. VERY WARM AND DRY UNDER THE RIDGE WITH TEMPERATURES
PUSHING TOWARD 100 ON FRIDAY. MORE UNCERTAINTY FOR THE WEEKEND AS
MODELS INDICATING SHORTWAVE/COLD FRONT SLIDING ACROSS MONTANA TO
FLATTEN OUT THE RIDGE AND COOL TEMPERATURES. GENERAL CONSENSUS OF
THE MODELS IS FOR COLD FRONT PASSAGE ON SATURDAY BUT WITH A DELAY
IN THE INFLUX OF COLDER AIR...MAKING FOR STILL TOASTY WEATHER
SATURDAY.

WITH THE FLATTENING OF THE RIDGE WILL ALSO COME A RETURN TO MORE
ACTIVE SHORTWAVE PATTERN...AND A RELATED INCREASE IN THUNDERSTORM
POTENTIAL. THIS SHOULD LAST THROUGH THE END OF THE FORECAST PERIOD
WHEN THE RIDGE REBOUNDS TO THE WEST. EBERT

&&

.AVIATION...
SCATTERED SEVERE THUNDERSTORMS MOVING ACROSS THE AREA TONIGHT WILL
REDUCE VISIBILITY BRIEFLY BELOW 3 MILES...AND A FEW WILL PRODUCE
LARGE HAIL THE SIZE OF GOLF BALLS AS WELL AS WINDS GUSTING TO 50
KT. CEILINGS MAY DROP BRIEFLY TO MVFR. THE STORMS WILL EXIT OUR
EASTERN ZONES VERY LATE TONIGHT. OTHERWISE VFR. SIMONSEN

&&

.CLIMATE...
IT LOOKS LIKE THIS JULY 4TH WILL BE SUNNY AND DRY IN GLASGOW.
HISTORICALLY THERE IS A GOOD CHANCE OF RAIN ON THE 4TH OF JULY.
THERE HAS BEEN RAIN IN GLASGOW 9 TIMES ON THE 4TH OF JULY SINCE
1988. CB

&&

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

&&

WEATHER.GOV/GLASGOW

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
904 AM MDT MON JUL 2 2007

MTZ016>027-059>062-031200-
CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE-
RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS-
SOUTHWEST PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT-
904 AM MDT MON JUL 2 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT
SCATTERED THUNDERSTORMS WILL MOVE EAST ACROSS NORTHEAST MONTANA
TODAY AND TONIGHT. SOME OF THESE STORMS WILL BECOME SEVERE WITH
LARGE HAIL AND DAMAGING WINDS. THE BEST CHANCE OF SEVERE
THUNDERSTORMS WILL BE IN THE LATE AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

NO HAZARDOUS WEATHER EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
807 PM MDT MON JUL 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0740 PM     HAIL             6 SE OPHEIM             48.80N 106.31W
07/02/2007  M0.88 INCH       VALLEY             MT   TRAINED SPOTTER

&&

SIMONSEN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
824 PM MDT MON JUL 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0815 PM     HAIL             15 ESE LARSLAN          48.49N 105.89W
07/02/2007  E1.00 INCH       VALLEY             MT   PUBLIC

&&

JIMB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
849 PM MDT MON JUL 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0840 PM     HAIL             5 NNW VOLT              48.45N 105.76W
07/02/2007  E1.50 INCH       ROOSEVELT          MT   TRAINED SPOTTER

&&

JIMB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
906 PM MDT MON JUL 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0840 PM     HAIL             8 NE LUSTRE             48.48N 105.76W
07/02/2007  E1.25 INCH       ROOSEVELT          MT   PUBLIC

&&

BOGEL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
922 PM MDT MON JUL 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0910 PM     HAIL             2 SW PLENTYWOOD         48.75N 104.59W
07/02/2007  E0.75 INCH       SHERIDAN           MT   TRAINED SPOTTER

            WINDS ESTIMATED 40-45 MPH. VERY HEAVY RAIN FALLING

&&

JIMB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
959 PM MDT MON JUL 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0958 PM     TSTM WND GST     10 WNW MEDICINE LAKE    48.58N 104.69W
07/02/2007  E60 MPH          SHERIDAN           MT   TRAINED SPOTTER

            THE WIND WAS ACCCOMPANIED BY HEAVY RAINFALL.

&&

BOGEL