Damaging Winds in Washington, April 23, 2005

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SPOKANE WA
250 PM PDT SAT APR 23 2005

.SYNOPSIS...WEATHER DISTURBANCES WILL START TO MOVE INTO THE AREA
FROM THE SOUTH BRINGING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS TO EASTERN WASHINGTON AND NORTHERN IDAHO OVER THE
WEEKEND. DRIER CONDITIONS ARE EXPECTED TO RETURN FOR THE EARLY PART
OF NEXT WEEK.

&&

.DISCUSSION...

CORRECTED WORDING IN TONIGHT AND SUNDAY PARAGRAPH

TONIGHT AND SUNDAY...FOR THE REMAINDER OF TODAY INTO TONIGHT
SCATTERED SHOWERS AND THUNDERSTORMS OCCURRING OVER EASTERN OREGON AND
SOUTHWEST IDAHO WILL CONTINUE TO MOVE TO THE NORTH AND INTO EASTERN
WASHINGTON AND NORTHERN IDAHO. TODAYS/TONIGHTS SCENARIO SHOWS
INSTABILITY DUE TO THE HIGH THETA-E VALUES AND CAPE ELONGATED UP TO
HIGHER LEVELS OF THE ATMOSPHERE RATHER THAN PAST SPRING T-STORM
EVENTS WHICH HAD CAP VALUES MORE SQUASHED DOWN TO THE SURFACE AND
INSTABILITY GENERATED MORE FROM COLD POOLS OF AIR AT 500MB. THEREFORE
CURRENT PROGGED CAPES OF UP TO 500 J/KG SHOULD ALLOW MORE RESIDENCE
TIME IN THE UPDRAFT THAN RECENT PAST SPRING T-STORM EVENTS...ENOUGH
TO SUPPORT MENTION OF SMALL HAIL OVER THE SOUTHEAST. HAVE CONTINUED A
MENTION OF SHOWERS AND ISOLATED THUNDERSTORMS FOR THE FORECAST AREA
PER GFS DEPICTION OF 850MB THETA-E RIDGE AXIS ORIENTED FROM THE FAR
NORTHERN FRINGE OF THE CASCADE CREST DOWN SOUTHEAST TO THE LEWISTON
AREA FOR SUNDAY AS WELL. THIS THETA-E RIDGE AXIS IS COINCIDENT WITH
RATHER LARGE 850-700MB LAPSE RATES OVER THE RIDGE AXIS AND TO ITS
NORTHEAST. GFS DEPICTS QPF ORIENTED IN A SIMILAR MANNER ALONG THIS
THETA-E AXIS AS WELL.

SUNDAY NIGHT THROUGH TUES...DRYING TREND WILL BEGIN SUNDAY NIGHT...
WITH WHATS LEFT OF THE MID-UPPER LEVEL DEFORMATION BAND OF CLOUDS
AND PCPN FALLING APART AND MOVING SW INTO NRN ORE/SW WA. THIS PARTLY
IN RESPONSE TO A DEEPER DRIER AIR MASS MAKING ITS WAY OVER THE
CONTINENTAL DIVIDE BEHIND A WEAK COLD FRONT. THIS SLOW DRYING WILL
CONTINUE THRU MON AND INTO TUES UNDER THIS NELY FLOW AND RISING HTS
ALOFT AS THE UPPER RIDGE AXIS MOVES S THRU BC AND ALBERTA. COLD FRONT
AND RATHER IMPRESSIVE SFC ANTI-CYCLONE WILL WORK ITS SWD THRU ALBERTA
TUES. DEPTH OF COLD AIR WITH THIS FEATURE DAMMING SWD ALONG THE HI
PLAINS OF ALBERTA AND MONTANA DOESNT LOOK DEEP ENUF TO AFFECT A
DRAMATIC CHANGE IN EITHER WINDS OR PCPN FOR N ID BEFORE TUES NT. BZ

TUESDAY NIGHT THROUGH SATURDAY...MODELS IN AGREEMENT OF THE RIDGE
SHIFTING TO THE GULF OF ALASKA AS A LOW OVER CENTRAL CANADA
RETROGRADES WEST AND A LOW IN THE EASTERN PACIFIC NEARS
CALIFORNIA. THE LOW ACROSS CANADA WILL BRING A TROUGH SOUTHWEST OUT
OF CANADA...CREATING AN EASTERLY FLOW AND FAIRLY DRY CONDITIONS
THROUGH THURSDAY MORNING. GFS IS CREATING A CLOSED CUTOFF LOW OVER
THE INTERMOUNTAIN WEST THURSDAY...BUT RIGHT NOW IS THE ONLY MODEL
SHOWING THIS. WILL CONTINUE WITH MAINLY MOUNTAIN SHOWERS ACROSS
EASTERN WASHINGTON AND THE IDAHO PANHANDLE THROUGH THIS PERIOD AND A
RETURN TO SEASONABLE TEMPERATURES. /KOCH

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        49  67  44  68  42  69 /  60  30  10   0   0   0
COEUR DALENE  47  65  43  67  41  69 /  40  30  10   0   0   0
PULLMAN        47  64  43  65  41  67 /  60  50  30  10   0   0
LEWISTON       48  65  48  71  44  70 /  50  40  30  10   0   0
COLVILLE       44  64  42  71  40  70 /  30  20  10   0   0   0
SANDPOINT      44  62  43  68  40  67 /  30  20  10   0   0   0
WALLACE        38  58  40  61  37  64 /  40  40  20   0   0   0
MOSES LAKE     51  65  48  73  43  73 /  60  50  30   0   0   0
WENATCHEE      50  63  48  73  46  72 /  60  40  40  10   0   0
OMAK           51  70  45  73  42  71 /  50  50  10   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.

&&