514
FXUS65 KGJT 211136
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
536 AM MDT MON JUL 21 2025
KEY MESSAGES
- AFTERNOON SHOWERS AND STORMS DEVELOP OVER THE HIGH TERRAIN
EACH DAY.
- A WARMER, DRIER AIRMASS GRADUALLY MOVES IN FOR THE LATTER
HALF OF THE WEEK.
SHORT TERM /THROUGH TUESDAY/
ISSUED AT 517 AM MDT MON JUL 21 2025
THE WEST TEXAS HIGH HAS BROKEN DOWN, BUT THE HIGH OVER THE
MISSISSIPPI VALLEY AND THE LOW OVER SOCAL IS KEEPING EASTERN UTAH
AND WESTERN COLORADO UNDER A SOUTH TO SOUTHWESTERLY FLOW PULLING A
HEAVY MID-LEVEL DECK OF CLOUDS, REMNANTS OF AN MCC FROM MEXICO, INTO
THE REGION. A BAND OF LIGHT SHOWERS ARE TRACKING ALONG THE WESTERN
BOUNDARY OF THE CWA ALIGNED WITH THE RIGHT ENTRANCE REGION OF AN
OVERHEAD WEAK JETSTREAK WITH MORE ISOLATED OROGRAPHIC SHOWERS IN THE
FOUR CORNERS AREA AND TO THE NORTHEAST ON THE SAN JUANS. THE BAND OF
LIGHT SHOWERS WILL TURN MORE NORTHEASTERLY ACROSS NORTHWESTERN
COLORADO THROUGH THE MORNING AS THE JETSTREAK PULLS OUT TO THE EAST.
DIURNAL HEATING WILL TRIGGER THUNDERSTORMS OVER THE HIGHER TERRAIN
BY NOON, BUT THE CLOUD COVER WILL LIMIT CONVECTION TO ISOLATED TO
SCATTERED. SUBSIDENCE BEHIND THE JETSTREAK WILL SQUELCH THE
CONVECTION LATE IN THE AFTERNOON GENERALLY NORTHWEST TO SOUTHEAST
WITH ONLY SOME ISOLATED LINGERING SHOWERS OVER THE TERRAIN ALONG AND
SOUTH OF I-70 WITH MORE SCATTERED SHOWERS ALONG THE DIVIDE.
THE TROUGH IN THE PACIFIC NORTHWEST DROPS SOUTH INTO CALIFORNIA
OVERNIGHT INTO TUESDAY AND PUSHES THE NEXT SURGE OF MOISTURE MOSTLY
TO THE EAST OF THE THAT WILL LIMIT SHOWERS AND THUNDERSTORMS DIVIDE
LIMITING THE AFTERNOON THUNDERSTORMS TUESDAY AFTERNOON TO SCATTERED
ALONG THE DIVIDE WITH ONLY ISOLATED THUNDERSTORMS EXTENDING ONTO THE
FLAT TOPS, THE GRAND MESA AND THE UNCOMPAHGRE PLATEAU. TEMPERATURES
WILL RUN NEAR NORMAL IN THE NORTHWESTERN AREAS TO A LITTLE BELOW
NORMAL TO THE SOUTH AND EAST WHERE CLOUDS WILL LIMIT HEATING.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 334 PM MDT SUN JUL 20 2025
THE SYNOPTIC PATTERN OFFERS LITTLE DEVIATION FROM THE STATUS
QUO ON TUESDAY. THE TROPICAL MOISTURE PLUME CONTINUES TO DELIVER
ON PWAT'S IN EXCESS OF 30 PERCENT OVER NORMAL HERE ON THE WEST
SLOPE. THIS SHOULD BE ADEQUATE FOR CONVECTIVE INITIATION TUESDAY
AND WEDNESDAY ON AREA TERRAIN FEATURES. AREA TEMPERATURES WILL
REMAIN NEAR CLIMATOLOGY AS VALLEYS HEAT UP AHEAD OF AFTERNOON
CLOUDS AND SHOWER ACTIVITY. WEDNESDAY, A WAVE WORKING ALONG THE
CANADIAN BORDER LOOKS TO CHIP AWAY AT THE BIG HIGH COOKING MUCH
OF THE EASTERN CONUS. ASSUMING ALL GOES ACCORDING TO THE MODEL,
MOISTURE SUPPLIES GET SHUNTED EAST AND WE GET LEFT WITH REMNANT
MOISTURE THURSDAY. MODELS INDICATE SHOWER ACTIVITY LIMITED TO
CLOSER TO THE DIVIDE, BUT THIS FORECASTER LEANS IN TO A MORE
EXPANSIVE TERRAIN SHOWER SOLUTION THURSDAY, GIVEN THE TRACK
RECORD OF A LAG IN MOISTURE GETTING SCRUBBED FROM THE QUEUE.
THIS SHOULD ALSO INTRODUCE SOUTHWESTERLY FLOW BACK TO THE
REGION. TEMPERATURES BEGIN TICKING UPWARD TOO, AS WE RETURN BACK
TO A HOTTER, DRIER REGIME FRIDAY AND BEYOND. WINDS LOOK TO
REMAIN BELOW CRITICAL FIRE WEATHER THRESHOLDS, BUT IT SEEMS A
BIT PREMATURE TO RULE OUT SOME FIRE WEATHER COMING BACK INTO THE
PICTURE NEXT WEEKEND.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 517 AM MDT MON JUL 21 2025
A SCATTERED TO BROKEN MID-LEVEL CLOUD DECK HAS MOVED IN ACROSS
THE REGION WITH A FEW EMBEDDED LIGHT TERRAIN DRIVEN SHOWERS
SOUTHWEST OF A LINE KCNY-KTEX. BY 18Z, SCATTERED SHOWERS AND
THUNDERSTORMS WILL BUILD OVER THE HIGHER TERRAIN WITH THE
PRIMARY THREATS BEING LIGHTNING AND 25 KT OUTFLOW GUSTS.
CONVECTIVE ACTIVITY WILL DIMINISH NORTHWEST TO SOUTHEAST AFTER
21Z, COMING TO AN END BY 06Z OVER THE SOUTHERN MOUNTAINS. WINDS
WILL GENERALLY BE SOUTHWEST GUSTING 15-20 KTS BETWEEN 18Z AND
24Z AT MOST VALLEY TAF SITES, AND LIGHT OTHERWISE ACROSS THE
REGION.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
SHORT TERM...DB
LONG TERM...LTB
AVIATION...DB
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