STORM2K

What in the HECK are "Dry Showers?" I thought ALL showers were WET Check out this AFD:

THERE SHOULD BE AN INCREASE IN AFTERNOON CONVECTION
EACH DAY THRU MIDWEEK...MAINLY OVER THE WHITE MOUNTAINS AND EXTREME
EASTERN PORTION OF THE MOGOLLON RIM. MOISTURE WILL BE MAINLY MIDLEVEL
WITH LITTLE OR NO LOW LEVEL INCREASE EXPECTED...THUS EXPECTING
MOSTLY DRY SHOWERS TO DEVELOP ALONG WITH THE POTENTIAL FOR
LIGHTNING. FARTHER WEST...A DRY SOUTHWESTERLY FLOW WILL CONTINUE TO
BRING MOSTLY CLEAR SKIES ACROSS WESTERN AND CENTRAL PORTIONS OF THE
STATE.


Dennis

Maybe they mean *Virga*, which as most everyone would know, that is precipitation that starts to fall from the clouds but never makes it to ground level, evaporating in the very dry air in the low levels of the atmosphere.

Hmmm i wonder...


-justin-

Yeah, I knew that, I don't understand why when he wrote the AFD, he didn't simply say Viagra, I mean VIRGA! LOL!

Dennis

Here's the whole AFD:


AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
300 PM MST SAT JUN 19 2004

.SYNOPSIS...MOISTURE WILL SLOWLY INCREASE ACROSS THE SOUTHEASTERN
PORTION OF THE STATE OVER THE NEXT FEW DAYS...BRINGING AN INCREASE
IN CLOUDS AND A CHANCE OF MAINLY DRY THUNDERSTORMS. ELSEWHERE...A
DRY SOUTHWEST FLOW WILL RESULT IN MOSTLY CLEAR SKIES. EXPECT NEAR
NORMAL TEMPERATURES AND BREEZY AFTERNOON WINDS EACH DAY.

&&

.DISCUSSION...WATER VAPOR CHANNEL SHOWS A WEAK UPPER LEVEL
DISTURBANCE MOVING ACROSS SRN CALIF AND AZ THIS AFTERNOON. SOME THIN
CIRRUS CLOUDS ARE DEVELOPING WITH THIS FEATURE...BUT THESE SHOULD
CLEAR AFTER MIDNIGHT.

A WELL DEVELOPED EASTERLY FLOW CONTINUES TO PUSH ACROSS THE GULF OF
MEXICO AND INTO MEXICO TODAY...TURNING NORTHWARD ACROSS NRN MEXICO
INTO NM AND TX. SOUNDINGS ACROSS SRN TX AND NRN MEXICO SHOW DEEP
LAYER OF EASTERLY FLOW WITH MODERATELY HIGH PW VALUES. EXPECT THIS
WEAK SURGE TO CONTINUE AND ALLOW MOISTURE TO SLOWLY INCREASE ACROSS
THE SOUTHEASTERN PORTION OF AZ STARTING ON SUNDAY AND CONTINUING
INTO MIDWEEK. THERE SHOULD BE AN INCREASE IN AFTERNOON CONVECTION
EACH DAY THRU MIDWEEK...MAINLY OVER THE WHITE MOUNTAINS AND EXTREME
EASTERN PORTION OF THE MOGOLLON RIM. MOISTURE WILL BE MAINLY MIDLEVEL
WITH LITTLE OR NO LOW LEVEL INCREASE EXPECTED...THUS EXPECTING
MOSTLY DRY SHOWERS TO DEVELOP ALONG WITH THE POTENTIAL FOR
LIGHTNING. FARTHER WEST...A DRY SOUTHWESTERLY FLOW WILL CONTINUE TO
BRING MOSTLY CLEAR SKIES ACROSS WESTERN AND CENTRAL PORTIONS OF THE
STATE.

.EXTENDED...WESTERLY FLOW RETURNS LATER IN THE WEEK AND SCOURS OUT
THE SLIGHT BIT OF MOISTURE THAT FILTERED IN EARLIER BRINGING A
RETURN OF MOSTLY CLEAR SKIES TO ALL OF THE STATE. DB



Dennis

WELL....with this being the 2nd anniversary of the 2002 Rodeo Chediski Fire, the 1st year anniversary of the Kinishba Fire, things seem to be right on track for yet ANOTHER replay of the events. Fuel moisture content in the Live Fuels (living trees) is NOW down to 9% the trees are DEAD for all intents and purposes and they just don't know it yet......your home, if built out of lumber, comes out of the Dry Kiln with a moisture content of "10%"........

Check out this mornings forecast, pretty SCARY


posted June 20, 2004 07:36 AM
NATIONAL WEATHER SERVICE FLAGSTAFF AZ

345 AM MST SUN JUN 20 2004

.SYNOPSIS...MOISTURE WILL SLOWLY INCREASE ACROSS THE SOUTHEASTERN PORTION OF THE STATE OVER THE NEXT FEW DAYS...BRINGING AN INCREASE IN CLOUDS AND A CHANCE OF MAINLY DRY THUNDERSTORMS. ELSEWHERE...A DRY SOUTHWEST FLOW WILL RESULT IN MOSTLY CLEAR SKIES. EXPECT NEAR NORMAL TEMPERATURES AND BREEZY AFTERNOON WINDS EACH DAY.



TODAY...BECOMING PARTLY CLOUDY WITH A 10 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN IN THE AFTERNOON. LIGHT WINDS BECOMING SOUTHWEST AROUND 15 MPH WITH HIGHER GUSTS IN THE AFTERNOON. HIGHS 72 TO 82 ABOVE 7000 FEET...80 TO 89 BELOW 7000 FEET.

TONIGHT...PARTLY CLOUDY WITH A 10 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN...CLEARING AFTER MIDNIGHT. WEST WINDS AROUND 15 MPH AND GUSTY IN THE EVENING BECOMING LIGHT. LOWS 37 TO 46 ABOVE 7000 FEET...45 TO 55 BELOW 7000 FEET.

MONDAY...BECOMING PARTLY CLOUDY WITH A 10 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN IN THE AFTERNOON. LIGHT WINDS BECOMING WEST AROUND 15 MPH WITH HIGHER GUSTS IN THE AFTERNOON. HIGHS 72 TO 82 ABOVE 7000 FEET...81 TO 89 BELOW 7000 FEET.

MONDAY NIGHT...PARTLY CLOUDY WITH A 10 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN. WEST WINDS AROUND 15 MPH AND GUSTY IN THE EVENING BECOMING LIGHT. LOWS 37 TO 46 ABOVE 7000 FEET...45 TO 55 BELOW 7000 FEET.

TUESDAY...PARTLY CLOUDY WITH A 20 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN. LIGHT WINDS BECOMING WEST AROUND 15 MPH IN THE AFTERNOON. HIGHS 70 TO 80 ABOVE 7000 FEET...79 TO 88 BELOW 7000 FEET.

TUESDAY NIGHT...PARTLY CLOUDY WITH A 20 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN. LOWS 38 TO 47 ABOVE 7000 FEET...46 TO 56 BELOW 7000 FEET
.
WEDNESDAY...PARTLY CLOUDY WITH A 20 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN. HIGHS 69 TO 79 ABOVE 7000 FEET...78 TO 87 BELOW 7000 FEET.

WEDNESDAY NIGHT...PARTLY CLOUDY WITH A 20 PERCENT CHANCE OF DRY THUNDERSTORMS...LITTLE OR NO RAIN. LOWS 38 TO 47 ABOVE 7000 FEET...46 TO 56 BELOW 7000 FEET.

I'm pretty sure what the met in charge meant by dry showers was the potential for "dry thunderstorms", where they are generate lightning strikes but little or no rain ...

SF

Never seen a forecast for dry thunderstorms. It's a shame that the fire season is looking bad, y'all just can't get a break out there .

Stormsfury wrote:I'm pretty sure what the met in charge meant by dry showers was the potential for "dry thunderstorms", where they are generate lightning strikes but little or no rain ...

SF

Sadly Mike, your right.....we prepare ourselves for this time of year, just enough moisture to create some very HIGH base, dry thunderstorms, not enough to kick the monsoon season into full swing, happens every year. I knew what he meant, I was just being VERY sarcastic!

Dennis

are very common here during the runup to the monsoon and even more common elsewhere in the West. Cloud bases in these storms can run upwards of 15000 ft MSL or so and the CG lightning is more intense than with low based storms because of the higher field potential needed to spark across the longer clear air path. Threshold values for high basers for CG can run up to 20000 V/m vs the usual 650 V/m or less for FL storms.

Steve

Aslkahuna wrote:are very common here during the runup to the monsoon and even more common elsewhere in the West. Cloud bases in these storms can run upwards of 15000 ft MSL or so and the CG lightning is more intense than with low based storms because of the higher field potential needed to spark across the longer clear air path. Threshold values for high basers for CG can run up to 20000 V/m vs the usual 650 V/m or less for FL storms.

Steve

This is also why that "bolts from the blue" - or CG strikes that start from the anvil of a well-developed CB and strike well away from the actual core (miles away from the parent thunderstorm) are so dangerous because of the spark's much higher intensity to overcome air's poor conductivity.

SF

Maybe dry showers contain rain with no water...if that made any sense

LMAO @ dry showers lol

were not so dry today to the tune of 0.40in of rain which is the most rain we've had since early April.

Steve

The monsoon is going to try to make it out to the far West Coast as well:

My NWS at 9:30 PM 6/21/04 wrote:THE BIGGEST CHANGE IN OUR WEATHER WILL BE A SHIFT IN THE DRY NORTHERLY FLOW ALOFT TO A MORE SOUTHEASTERLY DIRECTION AS A 700 MB HIGH BUILDS OVER NEW MEXICO MIDWEEK. THE SOUTHEAST FLOW AROUND THIS HIGH WILL ADVECT VERY WEAK MONSOON FLOW INTO THE REGION WEDNESDAY
THROUGH SATURDAY. MEAGER MOISTURE WILL PREVENT ANY CONVECTIVE PRECIP FROM FORMING OVER THE MTNS...BUT COULD BRING MOUNTAIN CUMULUS EACH AFTERNOON.

they are being optimistic as the pattern we are seeing is not one of the monsoon which involves more than a shift in the flow at 700 mb but rather a reversal of flow through most of the troposphere. We are seeing right now a flow from a weak ULL off Baja and the aforementioned High but the monsoon is not fully established in Mexico which it has to be before it reaches us. We call this type of pattern a "false start".

Steve