Flash Flood in Oregon, July 14, 2001

SOUTHWEST OREGON/NORTHERN CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
230 PM PDT SAT JUL 14 2001

...A COOLING TREND...

MODELS AGREE THAT JET MAX NOW DIVING SOUTH ALONG BRITISH COLUMBIA
COAST WILL CREATE CLOSED LOW N OF SEATTLE BY MONDAY MORNING. THE
RESULT WILL BE A CHANCE OF SHOWERS OVER THE NORTHERN ZONES AND
TRANSITION TO BELOW NORMAL TEMPS FOR THE FIRST HALF OF THE NEW WEEK.

TONIGHT...IMMEDIATE CONCERN WILL BE ISOLD EVENING CONVECTION OVER N
CALIORNIA, SISKIYOU MTNS, AND CASCADES CREST EASTWARD. ALREADY
EXPANDED ISOLD TSRA WEST TO COVER ALL OF SISKIYOU COUNTY GIVEN RAPID
CU DEVELOPMENT ON AFT VIS IMAGERY. DAYTIME HEATING IS BEING
SUPPLEMENTED BY SYOPTIC SCALE LIFT AND WEAK UPPER DIFFLUENCE AS
CLOSED VORT CIRCULATION MOVES ACROSS CENTRAL CA. OTHERWISE EXPECT A M
CLEAR NIGHT WITH WIDESPREAD LOW CLOUDS AND FOG REDEVELOPING OVER COOS
CO AND VCNTY BROOKINGS.

SUNDAY...MODEST QVECTOR H7-H3 DIVERGENCE/SUBSIDENCE AND LACK OF
SIGNIFICANT MOISTURE ON TIME/HEIGHT SECTIONS SUPPORT MOSTLY TO PARTLY
SUNNY SKIES. MORNING LOW CLOUDS AND FOG WILL AGAIN BURN OFF OVER COOS
CO AND VNCTY OF BROOKING. WEAK INSTABILITY AND 325K 700MB THETA-E
CONTOUR SUPPORT SLIGHT CHANCE OF LATE DAY T-STORMS ALTURAS AND LAKE
COUNTIES.

SUNDAY NIGHT...GOOD MARINE PUSH AS MODEST QVECTOR CONVERGENCE AND
BAND OF H85-H7 MOISTURE SWEEP SE ACROSS S OREGON AS JET MAX ROUNDS
BASE OF UPPER TROUGH. WILL MAINTAIN CHANCE OF SHOWERS N OF UMPQUA
DIVIDE AND N CASCADES. WILL ALSO THROW IN CHANCE POPS FOR N ZONE 30
OTHERWISE JUST INCREASING CLOUDS OVER OREGON ZONES.

MONDAY...MID LEVEL MOISTURE AXIS SHIFTS EAST OF CASCADES ALONG WITH
MODERATE H7-H3 QVECTOR CONVERGENCE. CONSEQUENTLY, EXPECT M CLOUDY
SKIES EAST OF CASCADES AND NE CALIFORNIA. PER COORDINATION W/ CA
WFOS WILL INSERT SLIGHT CHANCE OF SHRA/TSRA CAZ082>085. P SUNNY IN
ROGUE BASIN, BUT LOW CLOUDS MAY LAST THRU MOST OF DAY IN THE UMPQUA
BASIN.

EXTENDED...THE PERIOD WILL BEGIN UNSEASONABLY COOL AS A CLOSED LOW
LIFTS NE THRU BRITISH COLUMBIA WITH A LONGWAVE 500MB TROUGH EXTENDING
S ALONG THE W COAST. AS A RESULT, TUE MAY WELL BE THE COOLEST DAY OF
ENTIRE WEEK WITH MAX TEMPS AT LEAST 10-15F BELOW NORMAL. 12Z AVN RUN
DOES SUGGEST SOME WEAK TO MODERATE FORCING OVER THE AREA, BUT H85-H5
MOISTURE APPEARS LIMITED, THUS WE WILL CONTINUE TO CONFINE ANY
SHOWERS TO THE N COAST, UMPQUA BASIN AND N CASCADES (CRATER LAKE).
AFTER TUE THE MRF ENSEMBLES/ECMWF AND CANADIAN ALL LIFT THE LOW NE
INTO CENTRAL CANADA WITH A LINGERING TROF ALONG THE W COAST AND HOT
RIDGE PARKED OVER THE S PLAINS. THE RESULT WILL BE A SLOW RETURN TO
NEAR NORMAL TEMPS BY SAT, JULY 21ST AS A WEAK SFC THERMAL LOW
REESTABLISHES OVER THE GREAT BASIN.

WOLF

.MFR...SMALL CRAFT ADVISORY FROM FLORENCE OR TO PT ST GEORGE CA.

OTH EE 051/062 049/062 050 140232
4BK EE 050/064 048/064 050 140012
RBG EE 053/077 052/074 049 140022
MFR BE 055/083 053/078 052 140011
LMT BE 044/079 044/074 044 142011
LKV BE 047/076 044/073 043 142112
MHS BE 048/079 048/075 046 141002