High Wind in Montana, January 20, 2002

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MST SUN JAN 20 2002

.SHORT TERM...NW FLOW ALOFT WILL BE OVER THE AREA TONIGHT WITH A
SHORTWAVE SKIRTING E NEAR THE CAN BORDER. ON MON THE FLOW WILL BACK
TO WSW AHEAD OF A STRONGLY POSITIVELY TILTED SHORTWAVE WHICH IS
FORECAST TO MOVE THROUGH THE AREA MON NIGHT. TUE SHOULD SEE A BREAK
IN SHORTWAVE ACTIVITY BEFORE ANOTHER SHORTWAVE MOVES THROUGH THE AREA
TUE NIGHT. ON WED MOIST ANTICYCLONIC NW FLOW ALOFT SHOULD BE OVER THE
AREA. LOW LEVEL DOWNSLOPE SHOULD RULE OVER THE PLAINS AND IN THE
VALLEYS SO WILL GO WITH 10 OR LESS POPS. EXCEPTIONS FOR THE LOWER
ELEVATIONS WILL BE NUMBER ONE...IN THE SW ETA/AVN INDICATE SOME LOW
LEVEL CONVERGENCE DEVELOPING AHEAD OF MON NIGHTS SHORTWAVE. MODELS
ALSO FORECAST AN ALMOST UNSTABLE AIRMASS. WILL GO WITH SOME 20 AND 30
PCT POPS FOR THIS MON AFTERNOON AND NIGHT. NUMBER TWO WILL BE IN THE
N FOR TUE NIGHT...AVN/ETA SLIP MODIFIED ARCTIC AIRMASS INTO FAR NRN
MT ON TUE WHICH SHOULD CONTINUE INTO TUE NIGHT. COMBINATION OF MOIST
AIRMASS...LACK OF DOWNSLOPE AND PASSAGE OF SHORTWAVE COULD LEAD TO A
LITTLE SNOW IN THAT AREA. AS FOR HIGH WINDS...WILL ONLY KEEP HIGH
WIND WARNING FOR THE ROCKY MOUNTAIN FRONT AND ERN GLACIER COUNTY INTO
THIS EVENING. FARTHER E 700 MB WINDS ONLY ARE FORECAST TO BE FROM 45
TO 55 KNOTS TONIGHT AND LOCAL APPLICATION PROGRAM DOES NOT INDICATE
SUPPORT HIGH WINDS. MAY HAVE TO WATCH OUT FOR HIGH WINDS AGAIN ALONG
THE FRONT WED AFTERNOON AS AVN HAS 700 MB WINDS TO 60 KNOTS WITH AN
INCREASING DOWNSLOPE SURFACE PRESSURE GRADIENT. BLANK

.EXTENDED...NO MAJOR CHANGES IN EXTENDED MODEL SOLUTIONS. ECMWF...
UKMET AND MRF ALL QUITE SIMILAR THOUGH MRF CONTINUES TO PROGRESS
SLIGHTLY FASTER. UPPER LEVEL HIGH PRESSURE RIDGE BEGINS BUILDING OVER
WESTERN CONUS THURSDAY WITH A MOIST FLOW ALOFT OVER CWA. GUSTY WIND
EXPECTED OVER NORTHERN CWA THURSDAY WITH SURFACE HIGH OVER GREAT
BASIN AND SURFACE LOW TRACKING ACROSS SOUTHERN CANADA. LOW SAGS
FURTHER SOUTH FRIDAY INCREASING THE WIND SLIGHTLY AND ALLOWING COOLER
AIR TO BEGIN FILTERING INTO CWA. ZONAL FLOW THEN DOMINATES SATURDAY
WITH AN EMBEDDED DISTURBANCE SKIRTING BY THE SOUTHERN CWA. LARGE
UPPER LEVEL LOW PRESSURE TROUGH THEN BEGINS MOVING INLAND LATE
SATURDAY AND OVER THE CWA SUNDAY FOR DECREASED WIND AND A CHANCE OF
PRECIPITATION MOST AREAS.

.CCF NUMBERS
GTF NN 024/036 018/030 014 04001
CTB NE 022/034 016/027 008 04001
HLN EE 024/036 018/030 015 04122
   EEEEE 030/018 034/020 038/016 032/014 030 11121123332
BZN EE 018/034 014/026 010 04123
   EEEEE 025/014 034/018 033/016 030/012 028 11132223333
WEY EE 005/021 002/016 902 04335
   CEEEE 015/005 023/006 021/004 018/001 017 33354445554
DLN EE 018/033 014/025 010 04122
   CEEEE 026/014 033/018 032/016 030/015 030 11132334432
HVR BC 016/036 014/025 008 04111
   CNNEE 020/011 040/018 038/012 026/010 025 12121112221
LWT NE 022/034 014/030 012 04001
   ENNEE 030/018 038/023 037/020 035/018 033 11111112221

.TFX...HIGH WIND WARNING INTO EARLY THIS EVENING ROCKY MOUNTAIN
FRONT AND EASTERN GLACIER COUNTY ZONES 9...10...AND 48.

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
308 PM MST SUN JAN 20 2002

TIME(MST)  .....EVENT  LOCATION..... ST   ...EVENT/REMARKS...........
           .....COUNTY LOCATION.....

0109 PM    CUT BANK                  MT   NON TSTM WIND 62 MPH
01/20/02   GLACIER                        CUT BANK MUNICIPAL AIRPORT

1230 PM    2 NE CHOTEAU              MT   NON TSTM WIND 66 MPH
01/20/02   TETON                          CHOTEAU AIRPORT

1230 PM    PENDROY                   MT   NON TSTM WIND 66 MPH
01/20/02   TETON                          DOT SITE