Severe Thunderstorm Warning 30, NWS Salt Lake City, UT

UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
230 PM MDT SAT AUG 3 2002

.SYNOPSIS...SOUTHWEST FLOW ALOFT WILL SPREAD A DRY AIR MASS OVER THE
AREA TONIGHT AND SUNDAY.  THE FLOW TURNS MORE SOUTHERLY MONDAY WHICH
WILL BRING SOME MOISTURE BACK INTO EASTERN UTAH.

.DISCUSSION...SCATTERED MOSTLY TERRAIN TRIGGERED CONVECTION THIS
AFTERNOON WILL FOLLOW THE NORMAL DIURNAL WEAKENING THIS EVENING.
STILL SOME QUESTION IF ANY OF NORTHWEST UT WILL BE ABLE TO TRIGGER
TODAY BUT WILL WAIT UNTIL NEAR ISSUE TIME TO DECIDE WHERE AND HOW
MUCH THREAT TO PUT IN THAT AREA.  THE DRIER AIR THAT IS WORKING INTO
WESTERN UT IS EXPECTED TO SPREAD ACROSS MOST OF THE REMAINDER
FORECAST AREA FOR SUNDAY FOR A MOSTLY SUNNY DAY.  THERE MAY STILL BE
ENOUGH MOISTURE/INSTABILITY FOR SOME LIMITED ACTIVITY OVER THE
MOUNTAINS OF SOUTHEAST ID BUT THATS ABOUT IT.  ALSO EXPECT BREEZY
CONDITIONS TOMORROW WHICH ALONG WITH LOWER HUMIDITIES WILL MAKE FIRE
BEHAVIOR A LITTLE MORE AGGRESSIVE AGAIN.  WE WILL ISSUE A RED FLAG
WARNING FOR TOMORROW IN THE AFTERNOON FIRE WEATHER PACKAGE.

OVERALL SYNOPTIC PATTERN FOR THE NEXT WEEK HAS THE LOW IN THE
EASTERN GULF OF ALASKA DEEPEN AND SHARPEN SOUTHWARD.  THIS CAUSED BY
LOW NEAR THE ALEUTIANS MOVING EAST AND KICKING OUT A SERIES OF
SHORTWAVES THAT FORCES THE RIDGE AXIS NOW NEAR 150W EAST AND THEN
SUPPRESSES IT LATER IN THE WEEK. MEANWHILE A HIGH CENTER WANDERS
AROUND THE MID PART OF THE COUNTRY.  THE 12Z MODELS TURN THE FLOW
OVER AZ MUCH MORE SOUTHERLY BY SUNDAY AFTERNOON THROUGH MIDDAY
MONDAY WHICH BRINGS A SURGE OF MOISTURE NORTHWARD OVER EASTERN UT
SUNDAY NIGHT AND MONDAY.  PLENTY OF MOISTURE TO OUR SOUTH SO IF THE
FLOW PATTERN IS CORRECT IT WONT TAKE LONG TO MOISTEN THE EAST AGAIN.
WILL ADD A CHANCE OF THUNDERSTORMS TO THE MOUNTAINS SOUTH OF THE WY
BORDER AND A SLIGHT CHANCE TO THE EASTERN VALLEYS.

BY TUESDAY THE FLOW IS MORE SOUTHWEST AGAIN AND DRIER CONDITIONS
FORECAST.  THEN FROM WEDNESDAY ON THE FLOW OVER AZ GOES SOUTH TO
SOUTHEAST FOR THE REMAINDER OF THE WEEK WHILE A SOUTHWEST FLOW
CONTINUES OVER THE NORTHERN GREAT BASIN.  MOISTURE SHOULD WORK
SLOWLY BACK INTO THE SOUTHEAST PART OF THE AREA TO BRING A THREAT OF
THUNDERSTORMS AGAIN BY THURSDAY AFTERNOON. THAT THREAT SPREADS
SLOWLY NORTH AND WEST FOR FRIDAY AND SATURDAY.  THE MORE WESTERLY
COMPONENT OF THE FLOW OVER THE NORTHERN SECTIONS SHOULD KEEP IT DRY
THERE.  EXPECT THE BOUNDARY BETWEEN THE MOIST AND DRY AIR TO BE
SOMEWHERE NEAR A LINE FROM THE UINTAS TO ELY.  IT SHOULD ALSO GET
WARMER OVER THE NORTH WITH 700MB TEMPERATURES FORECAST TO STEADILY
RISE FROM WEDNESDAY THROUGH SATURDAY.

SLC 2000  CDC -000  SANDERS

.SLC...RED FLAG WARNING SUNDAY FOR ALL UTAH MTNS AND WRN VALLEYS.