Daily Forecast

SHORT TERM

TODAY THROUGH SUNDAY NIGHT...

A BROAD AREA OF HIGH PRESSURE ENCOMPASSED THE DESERT SOUTHWEST AND
SOUTHERN ROCKIES EARLY THIS MORNING. THE CIRCULATION CENTER OF THE
HIGH WAS DIRECTLY OVER WEST-CENTRAL COLORADO AND EAST-CENTRAL UTAH.
MEANWHILE...A WEAK SHORTWAVES ENTRAINED IN THE CIRCULATION OF THE
HIGH WAS RESPONSIBLE FOR LATE NIGHT CONVECTION OVER THE SOUTHERN TIP
OF LAKE POWELL. DEEP MOISTURE REMAINED OVER THE SOUTHERN HALF OF THE
CWFA WHERE DEW POINT VALUES RANGED FROM THE MID TO UPPER 50S. THE
AIRMASS WAS MARGINALLY DRIER OVER THE NORTH WHERE DEW POINTS WERE
GENERALLY IN THE UPPER 40S.

THE MERIDIONAL STRATIFICATION OF MOISTURE APPEARED TO HAVE MUCH TO
DO WITH THE POSITIONING OF THE HIGH CENTER WHICH HAS BRIEFLY CUTOFF
THE INFLUX OF SUBTROPICAL MOISTURE TO THE NORTH. NOT TRUE ACROSS THE
SOUTH WHERE PRECIPITABLE WATER VALUES REMAINED ABOVE 1 INCH AND WILL
NOT CHANGE SIGNIFICANTLY TODAY. EXPECT DEEP MOISTURE IN CONCERT WITH
LIGHT STEERING WINDS AND CONSIDERABLE ANTECEDENT RAINFALL TO RESULT
IN ADDITIONAL EPISODES OF HEAVY RAIN INDUCED FLASH FLOODING AND MUD
AND ROCKSLIDES ACROSS THE SOUTH. CONSEQUENTLY...WILL CONTINUE THE
FLASH FLOOD WATCH FROM NOON THROUGH 9 PM THIS EVENING. DRIER
AIRMASS TO THE NORTH WILL LIKELY YIELD ISOLATED STORMS ACROSS THE
LOWER ELEVATIONS WITH SCATTERED THUNDERSTORMS OVER THE HIGHER
TERRAIN.

BOTH GFS AND NAM INDICATED SHEARING SHORTWAVE WILL ROTATE NORTHWARD
ACROSS THE WESTERN AND CENTRAL PORTION OF THE CWFA DURING THE LATE
NIGHT PERIOD AND INTO SUNDAY MORNING. MODEL POSITIONING OF THE
FEATURE WAS DIFFERENT WITH NAM TAKING MUCH OF THE ENERGY WEST OF THE
CWFA WHILE THE GFS DESCRIBED A PATH FARTHER TO THE EAST. DOUBTFUL
EITHER SOLUTION WILL VERIFY CLOSELY SO WILL CONTINUE WITH SOLUTION
THAT SATISFIES BOTH AS MOIST...UNSTABLE AIRMASS RIPE FOR NOCTURNAL
ACTIVITY.

MODELS CARRY THE HIGH CENTER EAST OF THE REGION LATER TONIGHT
ALLOWING MONSOON MOISTURE TO SURGE BACK INTO THE NORTHERNMOST REACHES
OF THE CWFA ON SUNDAY. BOTH NAM AND GFS INDICATED UPPER LEVEL
DIVERGENCE OVER THE AREA COMBINED WITH THE WEAK SHORTWAVE DISCUSSED
PREVIOUSLY. DYNAMIC FORCING WORKING IN CONCERT WITH DAYTIME HEATING
WILL RESULT IN INCREASED THUNDERSTORM COVERAGE NORTH...WITH SIMILAR
COVERAGE ELSEWHERE WHERE DEEP MOISTURE ALREADY IN PLACE. SOUNDINGS
STILL FAVOR SLOW MOVING STORMS...SO ADDITIONAL FLASH FLOODING LIKELY
SUNDAY AFTERNOON/EVENING...BUT WILL NOT ISSUE ADDITIONAL FF WATCH
WITH THIS PACKAGE. EXPECT SHORTWAVE ENERGY TO SUSTAIN SHOWERS AND
THUNDERSTORMS WELL INTO THE LATE NIGHT HOURS SUNDAY NIGHT.

INCREASED MOISTURE AND THUNDERSTORM ACTIVITY EXPECTED TO RESULT IN
COOLER TEMPERATURES ACROSS THE REGION TODAY AND SUNDAY AND MOS
GUIDANCE APPEARED TO CAPTURE THIS TREND WELL ENOUGH. GIVEN FAIRLY
PERSISTENT PATTERN EXPECT TO SEE LITTLE CHANGE IN OVERNIGHT LOWS.