176
FXUS63 KBIS 180259
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
959 PM CDT THU APR 17 2025
KEY MESSAGES
- ISOLATED RAIN AND SNOW SHOWERS ARE POSSIBLE (20 PERCENT
CHANCE) TONIGHT THROUGH FRIDAY.
- WINDY AND COLDER THIS AFTERNOON AND FRIDAY WITH HIGHS MAINLY
IN THE 40S. THE STRONGEST WINDS WILL BE THIS AFTERNOON IN THE
JAMES RIVER VALLEY.
- TRENDING WARMER FOR THE WEEKEND AND THE START OF NEXT WEEK.
- WIDESPREAD CHANCES FOR PRECIPITATION (30 TO 60 PERCENT) RETURN
MONDAY AND TUESDAY.
UPDATE
ISSUED AT 956 PM CDT THU APR 17 2025
DECIDED TO TAKE PRECIPITATION MENTION OUT OF THE SOUTH OVER THE
NEXT FEW HOURS. WE NEVER SAW ANY EVIDENCE OF ANYTHING REACHING
THE GROUND AND CHANCES SHOULD CONTINUE TO BE EVEN LOWER OVER THE
NEXT FEW HOURS. WE ALSO DECIDED TO GO AHEAD AND UPDATE THE SKY
COVER FORECAST THROUGH FRIDAY MORNING USING THE LATEST NBM
GUIDANCE. OTHERWISE, JUST BLENDED IN THE LATEST OBSERVATIONS TO
THE GOING FORECAST.
UPDATE
ISSUED AT 634 PM CDT THU APR 17 2025
NO MAJOR CHANGES WERE NEEDED FOR THIS UPDATE. HAVEN'T SEEN ANY
EVIDENCE OF PRECIPITATION REACHING THE GROUND ANYWHERE ACROSS
THE FAR SOUTH AT THIS POINT, EITHER FROM SURFACE OBSERVATIONS OR
WEBCAMS.
DISCUSSION
ISSUED AT 244 PM CDT THU APR 17 2025
THIS AFTERNOON, A CLOSED LOW WAS ANALYZED IN THE CENTRAL CANADIAN
PRAIRIES, WITH A SECONDARY LOW OVER THE SOUTHERN ROCKIES. AT THE
SURFACE, A DEEP LOW WAS MOVING INTO SOUTHERN MINNESOTA, WITH
SCATTERED SHOWERS AND THUNDERSTORMS CIRCULATING AROUND THE CENTER OF
THE LOW. ANY LIGHTNING ACTIVITY HAS STAYED EAST OF THE FORECAST
AREA, WITH ONLY A FEW SMALL AREAS OF RADAR RETURNS AND LIGHT RAIN
LEFT IN PARTS OF SOUTHERN NORTH DAKOTA. CEILINGS ARE STILL MODESTLY
HIGH ACROSS MUCH OF THE AREA, ALTHOUGH SOME LOWER CLOUD DECKS AROUND
4 TO 5K FEET HAVE BEEN DROPPING SOUTH FROM CANADA THROUGH THE EARLY
AFTERNOON. A TIGHT SURFACE PRESSURE GRADIENT HAS LED TO STRONG
NORTHWEST WINDS THROUGH THE DAY, GUSTING AROUND 40 MPH IN THE JAMES
RIVER VALLEY, CLOSEST TO THE CENTER OF THE LOW. AFTERNOON HIGHS WILL
BE IN THE MID 40S TO LOWER 50S, WITH THE CLOUD COVER AND WINDS
MAKING IT FEEL EVEN COOLER.
SYNOPTIC FLOW IS PROGGED TO BECOME SOMEWHAT SPLIT TONIGHT INTO
FRIDAY, AS A SOUTHERN STREAM TROUGH DIGS OVER THE SOUTHERN ROCKIES,
WHILE THE NORTHERN STREAM WAVE MOVES SOUTH FROM THE CANADIAN
PRAIRIES INTO NORTH DAKOTA. THE MAIN CHANGE WITH THIS FORECAST
UPDATE WAS TO BROAD BRUSH A 20 PERCENT CHANCE OF PRECIPITATION,
STARTING IN THE NORTH OVERNIGHT TONIGHT AND EXPANDING SOUTH THROUGH
THE DAY FRIDAY. THE LAST FEW RUNS OF HIGH-RES GUIDANCE HAVE BEEN
RELATIVELY CONSISTENT IN BRINGING IN WIDELY SCATTERED SHOWERS , IN
LINE WITH THE BASE OF THE NORTHERN STREAM TROUGH SWINGING THROUGH
THE STATE. WE EXPECT THESE TO BE PRIMARILY RAIN SHOWERS, ALTHOUGH
WITH COOLER TEMPERATURES, CAN'T RULE OUT SOME SNOW EITHER MIXING IN
WITH THE RAIN OR A TOTAL TRANSITION FROM RAIN TO SNOW. ANY
ACCUMULATIONS WOULD BE VERY LIGHT AND LIMITED TO GRASSY SURFACES.
COOLER TEMPERATURES AND BREEZY NORTHWEST WINDS WILL ACCOMPANY THE
CHANCES FOR SHOWERS, WITH HIGHS BACK INTO THE 40S ON FRIDAY.
THIS WEEKEND LOOKS MUCH MORE PLEASANT COMPARED TO TODAY AND
FRIDAY, AS A LOW AMPLITUDE UPPER RIDGE MOVES THROUGH THE
NORTHERN PLAINS REGION. EXPECT WIDESPREAD HIGHS BACK INTO THE
50S ON SATURDAY, AND THE 60S ON SUNDAY. SOUTHERLY WINDS WILL BE
A BIT LIGHTER ON SATURDAY, COMPARED TO 15 TO 20 MPH ON SUNDAY.
CLOUDS WILL BEGIN INCREASING ON SUNDAY AHEAD OF APPROACHING
CHANCES FOR PRECIPITATION.
ENSEMBLE CLUSTER ANALYSIS FAVORS BROAD SOUTHWEST FLOW ALOFT FOR THE
FIRST HALF OF NEXT WEEK, WITH A TROUGH PASSING THROUGH THE NORTHERN
ROCKIES INTO THE NORTHERN PLAINS AT SOME POINT MONDAY INTO TUESDAY.
LATEST NBM OUTPUT GIVES A BROAD 30 TO 60 PERCENT CHANCE OF
PRECIPITATION ACROSS THE AREA MONDAY THROUGH TUESDAY EVENING.
OVERALL P-TYPE IS STRONGLY FAVORED TO BE RAIN, ALTHOUGH CAN'T RULE
OUT SOME SNOW MIXING IN ACROSS THE NORTH TUESDAY MORNING. AT THIS
POINT THE PROBABILITY FOR ANY SUBSTANTIAL AMOUNTS OF LIQUID
PRECIPITATION IS MARGINAL, WITH A LOW CHANCE FOR EXCEEDING 0.50
INCHES OF RAIN OVER ANY 48 HOUR PERIOD. THERE COULD BE A FEW
THUNDERSTORMS IN THE MIX AS WELL, WITH DETERMINISTIC MODELS
ADVERTISING A COUPLE HUNDRED J/KG OF CAPE.
THERE IS HIGH CONFIDENCE IN SEASONABLE TEMPERATURES NEXT WEEK, WITH
MAX TEMPERATURES IN THE 50S AND 60S. THERE ARE SOME SIGNS OF A BRIEF
COOLDOWN FROM MONDAY TO TUESDAY, ALTHOUGH TEMPERATURES ARE STILL
FAVORED TO STAY NEAR NORMAL.
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 634 PM CDT THU APR 17 2025
BREEZY WINDS OUT OF THE NORTH WILL RELAX A BIT THIS EVENING WITH
THE EXCEPTION OF KJMS, WHICH MAY SEE BREEZY WINDS THROUGH THE
PERIOD. WE COULD SEE A FEW MVFR OR LOW VFR CEILINGS ACROSS THE
WEST AND NORTH FRIDAY MORNING, BUT VFR CONDITIONS ARE EXPECTED
OTHERWISE. THERE WILL BE A FEW ISOLATED SHOWERS FLOATING AROUND
WESTERN AND CENTRAL NORTH DAKOTA FRIDAY MORNING AND FRIDAY
AFTERNOON BUT CHANCES WILL BE LOW AT ANY GIVEN POINT (~20
PERCENT). THUS, WE HAVE NOT INCLUDED MENTION IN THE SITE
SPECIFIC TAF FORECASTS AT THIS TIME.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...ZH
DISCUSSION...JONES
AVIATION...ZH
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