Thursday, June 11, 2015

Pueblo NWS - A Record Forecast Discussion?

With a flood threat looming, NWS Forecaster Steve Hodanish has written an early morning Forecast Discussion (FD) that may be a contender for the longest and most detailed FD ever.

The first third or so goes:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
412 AM MDT THU JUN 11 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM MDT THU JUN 11 2015

.SIGNIFICANT FLASH FLOODING IS POSSIBLE FROM LATE THIS AFTERNOON
INTO TONIGHT ACROSS PARTS OF THE NWS PUEBLO COUNTY WARNING AREA...

IMPACT STATEMENT:

A SIGNIFICANT FLASH FLOOD/FLOOD THREAT WILL DEVELOP OVER PARTS OF THE
REGION FROM LATE THIS AFTERNOON INTO TONIGHT. THIS WILL BE A HIGH
IMPACT EVENT AND IT WILL AFFECT A LARGE AREA OF THE NWS PUEBLO
FORECAST AREA. THE GREATEST THREAT WILL EXIST FROM THE EAST SLOPES
OF THE SOUTHERN MOUNTAINS(PIKES PEAK...WET MTNS...SANGRE DE CRISTO
MOUNTAINS) EASTWARD ACROSS ALL OF THE SOUTHEAST COLORADO PLAINS.
FLASH FLOODING OVER THE BURN SCARS COULD BE
SIGNIFICANT...POTENTIALLY DESTRUCTIVE. RESIDENTS OF MANITOU SPRINGS
SHOULD BE ON HIGH ALERT AFTER 3 PM TODAY. TRAVEL ACROSS THE ABOVE
MENTIONED REGIONS MAY BECOME DIFFICULT...IF NOT
IMPOSSIBLE...ESPECIALLY ALONG HIGHWAY 50 FROM PUEBLO TO THE KANSAS
BORDER. FLASH FLOODING COULD BE SIGNIFICANT IN ALL COMMUNITIES
TODAY...INCLUDING BUT NOT LIMITED TO... COLORADO
SPRINGS...PUEBLO...WALSENBURG...LA JUNTA...EADS...AND LAMAR.

METEOROLOGICAL DISCUSSION:

EVERY SINGLE COMPUTER SIMULATION THAT I LOOKED AT EARLY THIS MORNING
INDICATES THAT HEAVY RAIN IS GOING TO OCCUR FROM THE EAST SLOPES OF
THE SOUTHERN MOUNTAINS AND THEN EASTWARD ACROSS MOST...IF NOT
ALL...OF THE PLAINS. ANTECEDENT CONDITIONS FOR A SIGNIFICANT FLOOD
EVENT ARE IN PLACE AS THE GROUND IS SATURATED FROM ALL OF THE HEAVY
RAINS WE HAVE HAD DURING THE LAST COUPLE OF MONTHS. PRECIPITABLE
WATER VALUES FROM THE 00Z REGIONAL SOUNDINGS WERE RUNNING ABOUT 200%
ABOVE NORMAL...AND THESE VALUES ARE FORECAST TO INCREASE LATER TODAY
(POTENTIALLY INTO HISTORIC VALUES IF I AM READING THE SPC PWAT PAGE
CORRECTLY). AN UPPER LEVEL LOW...WHICH HAS INGESTED THE REMNANTS OF
TROPICAL CYCLONE BLANCA... WILL MOVE OVER THE REGION TONIGHT. THE
FOCUSING MECHANISM FOR THE FLOODING WILL BE A BOUNDARY WHICH WILL
MOVE DOWN THE PLAINS THIS AFTERNOON (DURING PRIME HEATING) AND WILL
BE OVER SOUTHEAST COLORADO FROM LATE THIS AFTERNOON INTO THIS
EVENING.

BASED ON CURRENT GUIDANCE...THE HEAVY PRECIP SHOULD BEGIN IN THE
PIKES PEAK REGION AFTER 3 PM...WITH THE HEAVY PRECIP DEVELOPING
SOUTH AND EASTWARD AS THE EVENING PROGRESSES. A VERY MOIST
ATMOSPHERE WILL BE IN PLACE AND DIFFLUENCE ALOFT WILL ALLOW FOR VERY
EFFICIENT PRECIPITATION PROCESSES TO OCCUR. FCST SOUNDING OVER THE
REGION SHOW VERY EFFICIENT WARM RAIN PROCESSES DEVELOPING AND STRONG
WARM AIR ADVECTION FROM 600 MB DOWN TOWARDS THE SURFACE.

The complete FD is at:

http://forecast.weather.gov/product.php?site=PUB&issuedby=PUB&product=AFD&format=CI&version=1&glossary=1

1 comment:

  1. Wow! And I used to cringe on NWS Abq discussions, over-dramatizing certain upper lows and troughs spiraling through every so often, and all they might do (and rarely did much). Talking about sunny, abundant sunshine or mostly sunny must have gotten old, like their talking about "dirty ridges" did during other periods.

    Now, I need to look up how much rain and destruction SE Colorado got.

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