Drought in Colorado, April 1 to 30, 2002

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
230 PM MST SUN MAR 31 2002

SHORT TERM DISCUSSION: STATE IS CURRENTLY UNDER NORTHWESTERLY FLOW
ALOFT WHICH EXTENDS APPROX 3655 MILES FROM THE KODIAK ISLAND OF
ALASKA SOUTHEASTWARD TO ALABAMA.  THERE EXISTS NUMEROUS RIPPLES OF
INSTABILITY IN THIS FLOW...HOWEVER THE BOU CWA WILL STAY DRY AND
STABLE THROUGH THE NEXT 27 HOURS AS THE MID AND HIGH LVL MOISTURE
AND STRONGEST WINDS ALOFT REMAIN TO THE NORTH OVER MT/WYO/ND/SD.
WESTERLY DRAINAGE FLOW AFTER SUNDOWN ON THE PLAINS WILL KEEP
STRATUS OUT TONIGHT. MON LOOKS LIKE ANOTHER LEE TROUGH DAY WITH
RELATIVE HIGH PRESSURE WEST OF THE DIVIDE. THIS WILL LIKELY BRING
SOME GUSTY WESTERLIES DOWN TO THE FOOTHILLS...CHEYENNE RIDGE AND
PERHAPS THE I-25 CORRIDOR. AN AREA OF WEAK UPWARD Q-G FORCING BEGINS
TO ENTER THE NORTHERN HALF OF THE STATE BY MIDDAY SO A HIGH WIND
SETUP NOT LIKELY AS MNT TOP LAYER OPENS UP. FIRST DAY OF APRIL WILL
BE ABOVE NORMAL WITH 700MB TEMPS APPROACHING THE 6-8 DEGC RANGE.
FREDIN

LONG TERM DISCUSSION:  IT LOOKS MORE AND MORE LIKE THE SHORTWAVE
PASSING OVER THE NRN ROCKIES MON NIGHT/TUE WILL MISS US.  MODELS
HAVE BEEN TRENDING SLIGHTLY SLOWER AND FARTHER NORTH WITH THIS
FEATURE.  AVN HAS BEEN MOST CONSISTENT AND IS NOW THE FARTHEST
SOUTH...STILL PRODUCING A LITTLE LIGHT SNOW ALONG THE NRN BORDER
TUE.  HOWEVER...THE SYSTEM IS CLEARLY ABOUT 100 MILES FARTHER NORTH
THAN THE AVN HAS IT TODAY...MATCHING THE ETA INITIALIZATION QUITE
WELL.  ETA SOLUTION REMAINS ABOUT THAT MUCH FARTHER NORTH WITH THE
JET RELATED PRECIPITATION...ACROSS ERN WY/NRN NEB PANHANDLE.  THIS
LOOKS GOOD.  REMAINING QUESTION IS THE HANDLING OF THE COLD/MOIST
SURFACE AIR WHICH SHOULD STILL COME IN EARLY TUE.  ETA WOULD SUGGEST
A SHALLOW AIR MASS BELOW 7 OR 8 THOUSAND MSL WHICH STALLS OUT JUST
AS IT REACHES DENVER...THEN BURNS OFF BACK TO THE NE CORNER BY THE
END OF THE DAY.  THIS SEEMS INCONSISTENT WITH THE ELY WINDS WHICH
CONTINUE ON THE PLAINS IN THE ETA THROUGH THE DAY.  I WILL BRING THE
COLD AIR IN A BIT FARTHER...HOLDING IT AT THE PALMER DIVIDE AND THE
FOOTHILLS.  IF THE PREFERRED ETA IS CORRECT...IT SHOULD BE CLEAR
ABOVE THE SHALLOW STRATUS.  THERE COULD BE SOME EROSION IN THE
AFTERNOON OR OVERNIGHT TUE NIGHT...BUT THIS IS HARD TO TELL.  THERE
COULD BE SOME DRIZZLE OR FLURRIES IN THE COLD AIR...BUT CHANCE OF
MEASURABLE PRECIPITATION SEEMS QUITE LOW.

FOR WED THROUGH SUN...SE WINDS ON THE PLAINS WILL PROBABLY HOLD THE
COLD AIR IN THE NE CORNER...THOUGH IT COULD WARM UP NICELY AROUND
DENVER AS THE SHALLOW COLD AIR DEPARTS.  DEFINITELY WARM AGAIN AFTER
THAT.  THERE IS GOOD AGREEMENT ON THE RIDGING OVER THE NRN
ROCKIES...LESS ON OTHER UPSTREAM FEATURES.  CONSENSUS OF ENSEMBLES
CONTINUES TO BE MORE BLOCKY AND SLOWER THAN THE OPERATIONAL
MRF...IMPLYING A STRONGER RIDGE OVER US LONGER.  MRF GUIDANCE
TEMPERATURES AROUND 70 ARE HELD BACK BY CLIMATOLOGY...IT WILL
PROBABLY BE EVEN WARMER. ANY REMNANTS OF SW LOW WOULD HAVE LITTLE
COLD AIR ALOFT AND SHOULD BE IN A QUITE DRY AIR MASS...SO CONVECTIVE
THREAT FOR OUR AREA SEEMS LOW.    GIMMESTAD

.DEN...NONE.