335
FXUS63 KFGF 192037
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
337 PM CDT SAT APR 19 2025
KEY MESSAGES
- NEAR CRITICAL FIRE WEATHER IS EXPECTED SUNDAY AFTERNOON.
DISCUSSION
ISSUED AT 337 PM CDT SAT APR 19 2025
..SYNOPSIS
MID/UPPER LEVEL PATTERN FEATURES SHORTWAVE RIDGING OVER THE NORTHERN
PLAINS, WHILE THE BROAD LONGWAVE TROUGH REMAINS SOUTH AND EAST. DEEP
DRY AIR WILL BE IN PLACE THROUGH SUNDAY, WHICH WILL PLAY A ROLE IN
FIRE WEATHER CONCERNS DURING PEAK MIXING SUNDAY AFTERNOON. A
PROGRESSIVE WAVE ARRIVES LATE MONDAY THROUGH TUESDAY, WHEN THERE IS
A 30 TO 60 PERCENT CHANCE FOR GREATER THAN 0.25" OF RAINFALL
(HIGHEST CHANCES IN THE DEVILS LAKE BASIN TUESDAY). PROBABILITIES FOR
GREATER THAN 0.5" ARE MUCH LOWER (20-30% IN THE DEVILS LAKE BASIN) AS
ENSEMBLES FAVOR LOCATIONS WEST FOR MORE ORGANIZED DEFORMATION
BASED ON 700MB CLUSTERS (GOOD AGREEMENT). BEYOND THIS WE TRANSITION
INTO A ZONAL PATTERN WITH A TENDENCY FOR SPLIT FLOW AROUND OUR
REGION. THIS DOES ALLOW FOR ANOTHER PROGRESSIVE WAVE TO PASS JUST TO
OUR SOUTH AND EAST THURSDAY INTO FRIDAY, WITH THE HIGHEST CHANCES
(20-30%) FOR GREATER THAN 0.25" SOUTH OF I-94. TEMPERATURES WILL TEND
TO BE ABOVE AVERAGE OVER THE NEXT 7 DAYS, THOUGH STILL WITHIN A
STANDARD DEVIATION OF MODEL CLIMATOLOGY.
..NEAR CRITICAL FIRE WEATHER SUNDAY
DEEP MIXING, ALMOST TO 700 MB, IS ADVERTISED BY GUIDANCE TO BE IN
PLACE THROUGH THE DAY SUNDAY, WHILE SURFACE TROUGH DEEPENS AHEAD OF
A STALLING FRONTAL ZONE TO OUR WEST. HIGH CLOUDS INCREASE LATER IN
THE AFTERNOON/EVENING, BUT SHOULD REMAIN THIN ENOUGH INITIALLY NOT
TO INHIBIT MIXING OVER OUR AREA. DUE TO EFFICIENT MIXING AND VERY DRY
AIR ALOFT TDS ARE MORE LIKELY TO FALL CLOSER TO THE 10TH PERCENTILE
OF GUIDANCE, AND WITH TEMPS IN MID TO UPPER 60S RH VALUES SHOULD
FALL TO THE 20-28% RANGE. HIGHEST WINDS ALOFT WILL BE AS A SOUTHWEST
LLJ PROGRESSES THROUGH THE REGION LATE TONIGHT AND SUNDAY MORNING
WITH LOWERING OF WINDS ALOFT AS WE APPROACH PEAK MIXING IN THE
AFTERNOON. WIND GUSTS 25 TO 30 MPH ARE LIKELY (NBM PROBS GREATER
THAN 60% FOR 30MPH+) WITHIN THE CENTRAL AND NORTHERN RED RIVER
VALLEY, HOWEVER BASED ON THE TIMING OF MIXING/WINDS ALOFT THESE
HIGHER GUSTS ARE MOST LIKELY AFTER SUNRISE THROUGH MIDDAY. THE
HIGHEST MIXED LAYER WINDS BASED ON SOUNDINGS DURING THE AFTERNOON
TEND TO FALL IN THE 20-25 MPH IN THE CENTRAL/NORTHERN RRV (TEENS IN
THE FAR SOUTH), WHICH LOWERS CONFIDENCE IN RED FLAG CONDITIONS BEING
ACHIEVED. HOWEVER, CONDITIONS WILL BE CLOSE AND WITH DRY FINER FUELS
IN PLACE NEAR CRITICAL FIRE WEATHER CONDITIONS CAN BE EXPECTED.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1232 PM CDT SAT APR 19 2025
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD ACROSS
EASTERN ND AND NORTHWEST MN, WITH AN AREA OF SHALLOW 5000-7000
FT AGL CU IN SOUTHEAST ND THAT ISN'T EXPECTED TO ESTABLISH A
CEILING AT KFAR DUE TO DRY AIR ALOFT (MAY DISSIPATE DURING PEAK
AFTERNOON HEATING). SURFACE HIGH PRESSURE OVER THE REGION IS
RESULTING IN LIGHT WINDS (TRENDING FROM WEST TO SOUTHWEST). AS
LOW PRESSURE BUILDS TO THE WEST THEN EVENTUALLY MOVE INTO OUR
REGION SURFACE GRADIENT WILL DEEPEN AND SOUTHEAST WINDS WILL
INCREASE TO THE 10-13KT RANGE OVERNIGHT. HIGHER SUSTAINED WINDS
15-20KT CAN BE EXPECTED SUNDAY, ALONG WITH GUSTS DURING DAYTIME
MIXING SUNDAY TO AROUND 25KT.
FGF WATCHES/WARNINGS/ADVISORIES
ND...NONE.
MN...NONE.
DISCUSSION...DJR
AVIATION...DJR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page