Severe Thunderstorm Warning 157, NWS Denver/Boulder, CO

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
230 PM MDT MON SEP 17 2001

H5 TROF AND THE QG ASCENT ASSOCIATED WITH IT ARE PROGGED TO CONTINUE
OVER NORTHEASTERN COLORADO THROUGH TONIGHT.  AMS WILL REMAIN MOIST
AND UNSTABLE SO WILL NOT CHANGE TO MUCH IN THE SHORT TERM.  SOME
DRYING IS INDICATED ON THE CROSS-SECTIONS ON TUESDAY WITH SOME
SUBSIDENCE IN THE MORNING.  ANOTHER WEAKER SHORT WAVE EMBEDDED IN
NORTHWESTERLY FLOW ALOFT MOVES ACROSS THE CWA HOWEVER DURING THE
AFTERNOON.  AMS WILL REMAIN RELATIVELY UNSTABLE TUESDAY...SO WILL
HOLD ONTO THE SCT POPS INHERITED FROM THE PREVIOUS FORECAST.  AS FOR
WEDNESDAY...DRIER NORTHWESTERLY FLOW ALOFT WILL BE OVER NORTHEASTERN
COLORADO.  SO DRY AND WARMER AT THAT TIME.  AS FOR THE EXTENDED...
LATEST AVN CONSISTENT WITH LAST NIGHTS MRF...BRINGS ANOTHER SHORT
WAVE ACROSS COLORADO LATE THURSDAY AFTERNOON AND THURSDAY NIGHT...SO
WILL ADD A CHANCE OF SHOWERS AND TSTORMS AT THAT TIME.  MRF HANGS ON
TO SOME QPF INTO SATURDAY...AS IT TRIES IMPORT SOME MOISTURE FROM
THE SOUTH.  WITH ZONAL WLY FLOW EVIDENT...WILL LEAVE THE REMAINDER
OF THE EXTENDED DRY FOR NOW.  COOPER

.DEN...NONE.

COZ030>051-172000-

HAZARDOUS WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1100 AM MDT MON SEP 17 2001

THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES

ADAMS     ARAPAHOE     BOULDER   CLEAR CREEK   DENVER       DOUGLAS
ELBERT    GILPIN       GRAND     JACKSON       JEFFERSON    LARIMER
LINCOLN   LOGAN        MORGAN    PARK          PHILLIPS     SEDGWICK
SUMMIT    WASHINGTON   WELD

SYNOPSIS...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE FORECAST AREA
THIS AFTERNOON AND TONIGHT.  AS SURFACE LOW PRESSURE DEEPENS OVER
NORTHEASTERN NEW MEXICO...LOW LEVEL UPSLOPE FLOW WILL STRENGTHEN
AND CONTINUE TO PUSH MOISTURE AGAINST THE EAST FACE OF THE MOUNTAINS.
THE INSTABILITY CREATED BY THE APPROACH OF THE UPPER TROUGH WILL ALLOW
SHOWERS AND THUNDERSTORMS TO FORM OVER THE MOUNTAINS AND OVERRIDE THE
COOLER AIR MASS IN PLACE OVER MOST OF THE NORTHEASTERN PLAINS.  WHILE
AMPLE SHEAR WILL BE PRESENT FOR ISOLATED SEVERE THUNDERSTORMS TO
FORM...CLOUDINESS OVER MUCH OF THE NORTHEASTERN PLAINS WILL PREVENT
MUCH OF THE NECESSARY HEATING TO OCCUR.  HOWEVER...SATELLITE IMAGERY
THIS MORNING SHOWS EROSION OF THE CLOUD DECK ESPECIALLY OVER THE PALMER
DIVIDE WHICH WILL ALLOW SUFFICIENT SURFACE HEATING THIS AFTERNOON FOR
POSSIBLE SEVERE THUNDERSTORM DEVELOPMENT THERE.

SCATTERED SHOWERS WITH EMBEDDED ISOLATED THUNDERSTORMS WILL CONTINUE TO
FORM OVER THE MOUNTAINS AND MOVE OFF THE FOOTHILLS OVER THE URBAN
CORRIDOR AND NORTHEASTERN PLAINS THROUGH THE AFTERNOON AND EVENING.
THE SHOWERS AND THUNDERSTORMS WILL INCREASE IN STRENGTH AND COVERAGE
LATER THIS AFTERNOON AND INTO THE EVENING.  ISOLATED SEVERE
THUNDERSTORMS WILL FORM OVER THE PALMER DIVIDE.  THESE STORMS MAY
PRODUCE LARGE HAIL...DAMAGING WINDS AND BRIEF HEAVY RAIN.
SPOTTER ACTIVATION WILL NOT BE REQUIRED.

ON TUESDAY...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS DURING THE
MORNING WILL DECREASE BY AFTERNOON AND EVENING.

GARD...WFO BOULDER