Drought in Utah, May 1 to 31, 2002

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
200 PM MDT TUE APR 30 2002

STRONG SOUTHWEST WINDS WILL CONTINUE INTO THE EVENING HOURS TONIGHT
AS PACIFIC LOW MOVES ACROSS THE WESTERN GREAT BASIN. DECENT THERMAL
GRADIENT FORMS AHEAD OF THIS SYSTEM LATE THIS AFTERNOON...THEN
MOVES RAPIDLY ACROSS THE REGION OVERNIGHT BRINGING 7H READINGS ON
THE ORDER OF 4-6 DEGREES CELSIUS LOWER THAN THOSE EXPERIENCED THIS
MORNING. AIRMASS EXTREMELY DRY SO FRONT WILL PASS THROUGH WITHOUT
GENERATING ANY PRECIPITATION. ONLY EXCEPTION IS ACROSS THE EASTERN
UINTAS WHERE LOW POPS APPEARS WARRANTED AS UPPER LOW AND
DEFORMATION AREA CONVERGE. DESPITE CAA OVERNIGHT...TEMPERATURES
UNLIKELY TO BE IMPACTED MUCH AS WINDS KEEP LOWER ATMOSPHERE MIXED.

CANADIAN AIRMASS DROPS SOUTHWARD AND HANGS NORTH OF THE I-70
CORRIDOR ON WEDNESDAY. TIMING SUGGESTS SHOWERS ASSOCIATED WITH THE
FRONT LIKELY TO SET IN DURING THE AFTERNOON. WILL MENTION SNOW LEVEL
AND ACCUMULATIONS FOR THE NORTHERN MOUNTAINS...THOUGH NOT EXPECTING
SIGNIFICANT SNOW AMOUNTS. SCATTERED POPS SHOULD SUFFICE FOR LOWER
ELEVATIONS ACROSS THE NORTH WITH LOW CHANCES FOR THE CENTRAL ZONES...
AND CONTINED DRY SOUTH. WINDS SHOULD BE PRETTY STRONG ACROSS THE
SOUTH ONCE AGAIN ON WEDNESDAY...THOUGH TEMPERATURES COOLER THERE...AS
OVER THE REMAINDER OF THE CWFA.

POSITIVELY TILTED TROF HANGS UP OVER THE CENTRAL AND SOUTHERN
PORTION OF THE CWFA WEDNESDAY NIGHT INTO THURSDAY BRINGING A
CONTINUED CHANCE OF SHOWERS. AIRMASS COLD ENOUGH TO BRING
THE THREAT OF FREEZING TEMPERATURES TO AREAS ALREADY INTO THE
GROWING SEASON. THEREFORE...WILL ISSUE SPS TO DISCUSS AREAS...
UNCERTAINTY...AND FORECAST LOWS. TEMPERATURES REMAIN COOL ON
THURSDAY...THOUGH EXPECT FEWER CLOUDS. FLOW BECOMES MORE ZONAL
THURSDAY NIGHT AS TROF FLATTENS IN RESPONSE TO NEXT TROF MOVING INTO
THE PACIFIC NORTHWEST. NL

FRIDAY-TUESDAY:  MIDRANGE MODELS ARE IN PRETTY GOOD AGREEMENT WITH
GOOD RUN-TO-RUN CONSISTENCY. PATTERN TAKES ON A MORE ZONAL
NATURE ON FRI WITH AN APPENDAGE HANGING OVER THE SOUTHWEST.  THIS
LOOP GETS ABSORBED IN THE FLOW AND MOVES EAST DURING THE
WEEKEND. MODELS INDICATE A SLIGHT CHANCE OF PRECIPITATION SAT AS
A RESULT. WILL NOT CHANGE THE FORECAST AT THIS TIME EXCEPT
TO ADD A SLIGHT CHANCE TO THE MOUNTAINS ON SAT.  THEN A STRONG LOW
PRESSURE SYSTEM MOVES DOWN FROM WESTERN CANADA WITH DEEP CUT OFF
CENTERED OVER VANCOUVER ISLAND B.C. BY SUNDAY AFTERNOON. SOUTHWEST
FLOW IS THE RESULT FOR OUR AREA. MODELS ARE SURPRISINGLY SIMILAR WITH
THIS SOLUTION. BY TUE THE MRF OPENS UP THE LOW AS IT MOVES EAST WITH
SOUTHWEST FLOW INCREASING.  TUE STILL TOO EARLY FOR ANY
PRECIPITATION FOR US WITH THIS SYSTEM.  HEFFERNAN

.GJT...RED FLAG WARNING UNTIL 1000 PM MDT FOR ALL FIRE WEATHER ZONES
EXCEPT UTAH FIRE ZONE 443.