Severe Thunderstorm Warning 68, NWS Glasgow, MT

NORTHEAST MONTANA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
209 PM MDT TUE JUL 4 2000

ON THE SFC AT 18Z AN INVERTED TROF RUNS FROM A LOW IN THE WESTERN
NEB PANHANDLE UP TO ANOTHER LOW OVR CYXE...TO THE EAST OF THE LINE
DEW POINTS JUMP UP QUITE A BITINTO THE 60/70 RANGE OVR WEST-CENTRAL
ND...TO THE WEST KHVR IS 31 FOR DEW POINT...GGW CWFA IS MOSTLY IN
THE 50S. N-NW WINDS ACROSS THE AREA SO FAR.

12Z SOUNDING IS NOT THAT IMPRESSIVE FOR SVR WX IN THE SHEAR
PROFILES...CAPPED PRETTY GOOD AT 700MB...HOWEVER ELEVATED MOUNTAIN
CONVECTION IN THE PAST AROUND THE AREA HAS NOT OBEYED THE 700MB CAP
RULE VERY WELL. -3 LI WITH 1.04 PWATS. SVR WX IS POSSIBLE...NOT AS
GOOD OF A BET AS THE LAST TWO DAYS ACROSS THE CWA.

SAX PIX SHOWS CONVECTION OVER CENTRAL MT...LOOKING AT GOES SOUNDER
DATA FOR LI/S AND CAPE...LI/S -3 TO -7 WITH CAPES IN THE 1000 J/KG
RANGE OVR EASTERN MT AT 18Z.

MESO ETA HAS DONE AN EXCELLENT JOB AS OF LATE FOR NEMONT WITH THE
CONVECTIVE TRENDS...WILL CONTINUE TO THE USE OF THE MODEL FOR THIS
PACKAGE. ON THE SFC AT 18Z...THE NGM AND MESO ETA HAD THE CLOSEST
SFC FIELDS WITH REALITY. ETA AND AVN WERE FURTHER SOUTH WITH THE LOW
OVR NEB...HAVING IT IN THE VICINITY OF GOODLAND KS.

THE MESO ETA FORMS AN MCC OVR ND TONIGHT FROM THE CONVECTION THAT IT
ANTICIPATES OVR CENTRAL MT TO MOVE ACROSS MY SOUTHERN ZONES AND BYZ/S
NORTHERN ZONES. TOMORROW... IT FORMS IT/S MCC OVER GGW/S CWFA AND
MOVES IT INTO NW ND OVERNIGHT. THURSDAY...AT 00Z IF THE MESO IS
RIGHT IT WILL BE BYZ/S TURN FOR THE MCC...AND WOULD MOVE INTO THE MY
SE ZONES OVERNIGHT.  THE PATTERN JUST CONTINUES THROUGH THE SHORT
TERM OF THE FORECAST AS THE FLOW REMAINS SW OVR THE AREA. THE
AVN...HITS MORE THE WESTERN MTS AND EXTREME SE MT INTO ND WITH THE
MCC DEVELOPMENTS...THE ETA 60HR IS CLOSE TO THE MESO WITH THE IDEAS
OF WHERE THE MCC/S WOULD DEVELOP. THE NGM KEEPS THE TRAIN OF MCC/S
GOING FROM KBTM TO KISN THROUGH THE PERIOD.  WILL GO WITH THE ETA
FAMILY.

FOR TONIGHT...MESO ETA SOUNDINGS SHOW 700MB COOLING BRINGING
CONVECTIVE TEMPS DOWN TO REACHABLE LEVEL BY 00Z. AT THAT TIME THE
SHORTWAVE MOVES THROUGH THE FLOW. OMEGA/S INCREASE AS THE WAVE
PUSHES THROUGH MY SOUTHEASTERN CWA. WITH THE CONVECTIVE COMPLEX NEAR
BY AND AMPLE MOISTURE WILL GO ABOVE GUIDANCE ON TEMPS.

WEDNESDAY...LOOKS LIKE ANOTHER DAY OF SVR WX FOR KGGW...THE ELEMENTS
ARE FALLING INTO PLACE AGAIN. VORT COUPLET OVR CWFA BY 2Z MOVING OUT
BY 8Z. ANOTHER BATTEN DOWN THE HATCHES DAY IN NEMONT. GOOD
DIRECTIONAL AND SPEED SHEAR...HOWEVER IT/S NOT A TYPICAL NEMONT
SOUNDING...LOOKS MORE LIKE A ALABAMA SOUNDING FOR HEAVY RAINERS.
LATER SHIFTS MAY HAVE ANALYZE THE SITUATION FOR A POSSIBLE FLASH
FLOOD WATCH FOR THE EASTERN CWFA ON WEDNESDAY. GOING TO FOLLOW NEW
MAV GUIDANCE.

THURSDAY...DING..DING ROUND FOUR. MESO ETA PINS BYZ MORE THAN
GGW...BUT LOOKING AT THE ETA 60HR VERSION...WHAT FORMS OVR BYZ/S
AREA SHOULD RUN INTO MY SOUTHEAST OVERNIGHT. TEMPS...GOING TO
CONTINUE WITH THE MAV GUIDANCE.                       PROTON

EXTENDED...RUN TO RUN CONSISTENCY OF THE MEDIUM RANGE MODELS HAS
BEEN VERY POOR THE PAST FEW DAY. HAVING PROBLEMS WITH RESOLVING
UPPER LOWS SPINNING OUT OF STRONG PACIFIC COAST TROF INTO WESTERN
CANADA AND WHETHER THEY WILL TRACK EAST AND KNOCK DOWN RIDGE OR
ROTATE BACK INTO TROF. DUE TO UNCERTAINTIES WITH MODELS WILL BROAD
BRUSH CHANCE OF THUNDERSTORMS WITH MOIST SOUTHWEST FLOW ALOFT
CONTINUING. EBERT

GGW TTTTT 060/080 060/085 058/087 058/086 060/090 945373/90333
GDV TTTTT 060/082 060/088 059/089 059/087 061/090 947373/90333