288
FXUS65 KGJT 311751
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1151 AM MDT SAT MAY 31 2025
KEY MESSAGES
- TEMPERATURES CONTINUE WELL ABOVE NORMAL TODAY AND TOMORROW,
BEFORE COOLING GOING INTO THE WORK WEEK.
- ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS CONTINUE ON THE
TERRAIN MOSTLY ALONG THE DIVIDE TODAY AND TOMORROW, WITH SOME
PRODUCING GUSTY WINDS AND OCCASIONAL LIGHTNING.
- A SURGE OF DEEP SUBTROPICAL MOISTURE IS EXPECTED TO ARRIVE
MONDAY PRODUCING WIDESPREAD RAINSHOWERS AND THUNDERSTORMS.
LOCALIZED FLOODING REMAINS A CONCERN NEXT WEEK, GIVEN SOME OF
THE FORECAST VALUES FOR AVAILABLE MOISTURE.
SHORT TERM /THROUGH SUNDAY/
ISSUED AT 317 AM MDT SAT MAY 31 2025
MODELS ARE IN GOOD AGREEMENT WITH SATELLITE IMAGERY WITH THE CUTOFF
LOW OFF THE BAJA COAST, A TROUGH APPROACHING THE PACIFIC NORTHWEST,
ANOTHER LOW DESCENDING OVER THE DAKOTAS WITH A FRONTAL BOUNDARY
SLIDING SOUTH INTO WESTERN NEBRASKA AND ALONG THE FRONT RANGE IN
EASTERN WYOMING. SUBSIDENCE UNDER THE HIGH PRESSURE BUILDING INTO
THE GREAT BASIN WITH RIDGING EXTENDING UP THROUGH THE INTERMOUNTAIN
WEST INTO ALBERTA HAS CLEARED OUT THE SKIES ACROSS MOST OF THE
MOUNTAIN STATES. THIS RIDGE WILL CONTINUE TO SLIDE EAST UNTIL IT IS
STRADDLING EASTERN UTAH AND WESTERN COLORADO BY SUNDAY MORNING.
THESE CLEAR SKIES ALONG WITH THE RIDGE MOVING IN WILL ALLOW
TEMPERATURES ACROSS THE REGION TO CLIMB TO TEN OR MORE DEGREES ABOVE
NORMAL ACROSS THE REGION TODAY AND TOMORROW, THE WARMEST
TEMPERATURES SO FAR THIS YEAR. LOOK FOR LOW TO MID 90'S IN MOST OF
THE LOWER VALLEYS ACROSS THE REGION WITH SOUTHEASTERN UTAH HITTING
THE CENTURY MARK, AND THE MOUNTAIN COMMUNITIES SEEING 70'S INTO THE
LOW 80'S. THOUGH DEWPOINTS HAVE DROPPED SOME, THERE IS STILL ENOUGH
MOISTURE AVAILABLE IN THE MOUNTAINS TO KICK OFF A FEW ISOLATED HIGH-
BASED AFTERNOON SHOWERS AND THUNDERSTORMS MOSTLY ALONG THE DIVIDE,
BUT CAN'T RULE OUT A STRAY SHOWER FARTHER WEST OVER THE FLAT TOPS,
ROAN CLIFFS AND GRAND MESA, OR EVEN ON THE UNCOMPAHGRE PLATEAU AND
UINTA MOUNTAINS. GUSTY OUTFLOW WINDS UNDER MOSTLY VIRGA AND A STRAY
LIGHTNING STRIKE ARE THE PRIMARY THREATS FROM THESE STORMS. BY
SUNDAY AFTERNOON WE WILL START TO SEE CLOUDS MOVING UP FROM THE
SOUTH AHEAD OF THE PLUME OF REMNANT SUBTROPICAL MOISTURE FROM
TROPICAL STORM ALVIN.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
ISSUED AT 242 PM MDT FRI MAY 30 2025
SUNDAY WILL BE THE WARMEST DAY OF THE PERIOD AND MOST LIKELY THE
WARMEST OF THE SEASON THUS FAR. DESERT VALLEYS WILL GET INTO THE 90S
AND PUSH 100 IN SPOTS , WHILE MOUNTAIN TOWNS GET INTO THE 70S AND
SOME THE 80S. THERE MAY BE ENOUGH MOISTURE FOR HIGH TERRAIN SHOWERS
AND STORMS MAINLY IN THE AFTERNOON. THEY WILL PRODUCE MORE WIND THAN
RAINFALL. ATTENTION THEN TURNS TO A CLOSED LOW PRESSURE OFF THE
COAST OF THE BAJA PENINSULA. ON SUNDAY IT WILL BEGIN TO LIFT
NORTHEASTWARD, WHICH SENDS IT ON A TRACK FOR OUR AREA. BEFORE
THAT HAPPENS IT WILL PICK UP MOISTURE FROM THE REMNANTS OF
TROPICAL STORM ALVIN IN THE EASTERN PACIFIC. ON MONDAY, THIS
SURGE OF MOISTURE ARRIVES ALONG WITH THE LOW PRESSURE THAT WILL
BE WEAKENING INTO AN OPEN SHORTWAVE TROUGH. NONETHELESS IT WILL
PROVIDE LARGE-SCALE LIFT THAT IN COMBINATION WITH THIS MOISTURE
WILL RESULT IN SCATTERED TO WIDESPREAD SHOWERS AND STORMS. THE
PWATS AT THIS TIME REACH 200-300 PERCENT OF NORMAL, WHICH IS
HIGHLY ANAMOLOUS. ONE OF THE MAIN UNCERTAINTIES IS THE TIMING OF
MOISTURE AND OR CLOUDS ON MONDAY. ANY LOCATIONS THAT ARE ABLE
TO GET SOME SUN WILL BE ABLE TO BUILD INSTABILITY. IF THE
INSTABILITY MATERIALIZES THEN THE CONVECTION THAT FORMS IN THE
AFTERNOON COULD BE CAPABLE OF PRODUCING HEAVY RAINFALL, HAIL AND
STRONG WINDS. THE OTHER SCENARIO IS MORE STRATIFORM WITH
EMBEDDED CONVECTION, WHICH WOULD MOST LIKELY PRODUCE MORE LIGHT
TO MODERATE RAINFALL.
THE OTHER COMPLICATED FACTOR WITH THIS TIME FRAME IS AN ACTIVE
NORTHERN STREAM, WHICH COULD SEND A FRONTAL BOUNDARY DOWN FROM THE
NORTH INTO THE MOIST AIRMASS ON TUESDAY AND WEDNESDAY. THIS WOULD BE
ANOTHER MECHANISM FOR FORCING SHOWERS AND STORMS. AT THAT SAME TIME
A SECOND LOW PRESSURE WORKS IT'S WAY INTO SOUTHERN CALIFORNIA
AND THE DESERT SOUTHWEST. THIS SYSTEM COULD ALSO INTERACT WITH
THE MOISTURE AS WELL AND CAUSE ADDITIONAL ROUNDS OF
PRECIPITATION. THAT SYSTEM IS CERTAINLY TOO FAR OUT TO GET INTO
THE DETAILS, BUT SOMETHING TO WATCH. IF THE SUN CAN DESTABILIZE
THE ATMOSPHERE ON TUESDAY AND WEDNESDAY THEN WE COULD BE LOOKING
AT THE POTENTIAL FOR HEAVY RAINFALL. MODEL CONSENSUS IS SHOWING
PROBABILITIES OVER 50% FOR THE CHANCE OF GETTING OVER AN INCH
OF LIQUID DURING THE 3-DAY PERIOD. PROBABILITIES REACH 30% FOR
OVER 2 INCHES IN THE SAN JUANS AND PARK RANGE. THIS COULD CHANGE
AND UNCERTAINLY IS HIGHER IF CONVECTION IS THE FAVORED MODE.
WITH ALL OF THE RAIN AND CLOUDS AROUND ON MONDAY THROUGH
WEDNESDAY TEMPERATURES GO WELL BELOW NORMAL.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1146 AM MDT SAT MAY 31 2025
VFR CONDITIONS WILL REMAIN IN PLACE AT MOST OF THE TERMINALS
TODAY AND TONIGHT. AFTERNOON SHOWERS AND THUNDERSTORMS ARE
EXPECTED ON TERRAIN TODAY. DEVELOPMENT OVER THE SAN JUANS IS
MORE BULLISH ATTM, SO KTEX RECEIVED PROB30 THIS AFTERNOON FOR
TSRA, WHILE NORTHWARD AT KASE LEFT JUST SHOWERS IN THERE.
CONFIDENCE IN SHOWER AND STORM PLACEMENT REMAINS LOW. A FEW OF
THESE SHOWERS WILL PRODUCE GUSTY OUTFLOW WINDS AND OCCASIONAL
LIGHTNING. STORMS WILL QUICKLY DIMINISH THIS EVENING AND VFR
WILL PREVAIL OVERNIGHT INTO SUNDAY MORNING AGAIN. AFTERNOON
WINDS WILL PICK UP TO AROUND 20 MPH AROUND THE TERRAIN, BUT
RETURN LIGHT AT SUNSET.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
SHORT TERM...DB
LONG TERM...KJS
AVIATION...TGJT
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