822
FXUS66 KOTX 181117
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
417 AM PDT MON OCT 18 2021
SYNOPSIS
MOST OF THE REGION WILL REMAIN DRY AND WARM THROUGH TUESDAY, BUT
LOOK FOR A MIX OF SUN AND CLOUDS. A PERIOD OF LIGHT RAIN IS
POSSIBLE WEDNESDAY. A WETTER PATTERN IS FORECAST FOR THE INLAND
NORTHWEST FOR THE END OF THE WEEK INTO NEXT WEEKEND, WITH
TEMPERATURES COOLING CLOSER TO NORMAL.
DISCUSSION
MONDAY AND TUESDAY: EASTERN WASHINGTON AND NORTHERN IDAHO WILL BE
ON THE NORTHERN FRINGE OF A DEEP TROUGH THAT IS TRACKING THROUGH
THE GREAT BASIN TODAY. THIS WILL BRING CLOUDS AND ANOTHER MILD,
SEASONAL TEMPERATURE DAY FOR THE REGION. TUESDAY WILL ACTUALLY
FEATURE MUCH OF THE SAME WEATHER AS WE BECOME INFLUENCED BY WEAK
RIDGING BETWEEN WEATHER SYSTEMS AND MAY SEE ONLY THE SLIGHTEST
CHANGE IN DAYTIME TEMPERATURES FOR LOCATIONS EAST OF THE CASCADES.
WEDNESDAY: OUR NEXT SET OF WEATHER SYSTEMS WILL BEGIN TO TAKE AIM
AT THE WEST COAST STARTING WEDNESDAY AND WILL REMAIN IN AN
UNSETTLED PATTERN FOR THE NEXT WEEK OR MORE. THE LONG RANGE
ENSEMBLE GUIDANCE WOULD SUGGEST SEVERAL SHORTWAVES WILL MOVE
THROUGH THE NORTHWEST WITH A PARENT TROUGH POSITIONED OFF THE
COAST OF WASHINGTON STATE/BRITISH COLUMBIA. OUR FIRST TROUGH ON
WEDNESDAY BECOMES NEGATIVELY TILTED BEFORE IT MOVES INLAND AND THE
MOISTURE PLUME IS MORE DIRECTED INTO NORTHERN CALIFORNIA AND
OREGON. BY THE TIME THE ENERGY FROM THE SHORTWAVE TRACKS THROUGH
NORTH CENTRAL OREGON INTO THE COLUMBIA BASIN AROUND THE CASCADES,
MUCH OF THE FORCING WILL AIDE IN THE TRACK OF THE WAVE NORTH INTO
CANADA AND WILL BRING MORE CLOUDS AND SOME LIGHTER PRECIPITATION.
RIGHT NOW THE FORECAST HAS AROUND 0.10" TO 0.15" OF PRECIP.
SOUTHERLY WINDS WILL BECOME BREEZY WITH GUSTS AROUND 10 TO 25 MPH.
THIS IS EXPECTED TO BE A TYPICAL RUN-OF-THE-MILL LIGHT RAIN FALL
DAY. /DEWEY
THURSDAY: LOOKING MORE AND MORE LIKE A DRY DAY - A BREAK BETWEEN
PRECIPITATION SYSTEMS. TEMPERATURES WILL RECOVER A LITTLE BIT FROM
A COOLER WEDNESDAY; ABOUT 5 TO 10 DEGREES ABOVE AVERAGE IN THE 60S
FOR MOST OF THE AREA. WINDS WILL BE RELATIVELY NORMAL WITH GUSTS
UP TO 20 MPH POSSIBLE IN THE COLUMBIA BASIN.
THURSDAY NIGHT THROUGH SUNDAY: A WETTER PERIOD WITH WIDESPREAD
RAIN AND BREEZY WINDS...AND MODELS DIVERGE GREATLY ON TIMING AND
INTENSITY. MAX TEMPERATURES WILL COOL TO THE 50S FROM THE CLOUD
COVER/RAINFALL AND WITH THE HELP FROM A COOLER AIRMASS MOVING IN
FRIDAY. HOWEVER SOUTHWEST FLOW AND WARM ADVECTION (AND THE EFFECTS
OF OVERNIGHT CLOUD COVER) WILL KEEP US FROM DROPPING TO WIDESPREAD
LOWS BELOW FREEZING.
THERE ARE 2 END OF THE WEEK SYSTEMS WE'RE KEEPING AN EYE ON.
* SYSTEM 1: ROUGHLY FRIDAY...MAY BEGIN THURSDAY NIGHT AND BE OUT
OF THE AREA FRIDAY AFTERNOON OR ARRIVE LATER AND EXIT SATURDAY
MORNING. LATEST MODEL RUNS SUPPORT POSSIBLY AROUND A QUARTER OF
AN INCH IN PARTS OF THE BASIN AND EASTERN WASHINGTON. THIS
SYSTEM ELONGATES AND WEAKENS WHEN IT REACHES THE COAST, SO IT
MAY STILL BE A COUPLE OF MODEL RUNS BEFORE THERE IS CONSENSUS ON
HOW MUCH IT SLOWS DOWN AND HOW MUCH RAINFALL IT CAN PRODUCE.
* SYSTEM 2: SATURDAY OR SUNDAY...DEPENDING ON WHICH MODEL SOLUTION
REALITY TILTS TOWARD. MUCH OF THE ENERGY ASSOCIATED WITH THE
FRIDAY SYSTEM REGROUPS NEAR THE GULF OF ALASKA AND APPROACHES
DURING THE WEEKEND, POTENTIALLY FROM THE SOUTHWEST INSTEAD OF
OUR TYPICAL CROSS-CASCADES SYSTEM. SATURDAY HAS A CHANCE AT
BEING ANOTHER IN-BETWEEN-SYSTEMS DAY, BUT NO PROMISES... RC
AVIATION
12Z TAFS: MID AND HIGH CLOUDS WILL FILTER INTO FAR SOUTHEAST WA
AND THE CENTRAL ID PANHANDLE TODAY. LIGHT DIURNALLY DRIVEN WINDS
AROUND 10 KTS OR LESS AND VFR CONDITIONS ARE EXPECTED THE NEXT 24
HOURS FOR AREA AIRFIELDS. /DEWEY
PRELIMINARY POINT TEMPS/POPS
SPOKANE 66 36 64 41 60 39 / 0 0 0 0 40 10
COEUR D'ALENE 65 37 63 40 58 39 / 0 0 0 0 40 10
PULLMAN 59 33 63 41 59 37 / 0 0 0 0 40 10
LEWISTON 66 42 68 47 65 44 / 0 0 0 0 40 10
COLVILLE 68 31 65 34 59 33 / 0 0 0 0 50 20
SANDPOINT 63 36 59 36 55 36 / 0 0 0 0 50 30
KELLOGG 67 41 63 44 60 39 / 0 0 0 0 40 20
MOSES LAKE 67 33 63 43 62 38 / 0 0 0 10 40 0
WENATCHEE 67 42 62 46 59 43 / 0 0 0 10 60 10
OMAK 68 38 66 43 60 40 / 0 0 0 0 60 10
OTX WATCHES/WARNINGS/ADVISORIES
ID...NONE.
WA...NONE.
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