Some Interesting Isaac Developments

I get away from the office for a few hours to do live weather and the HPC sends out a scary forecast for Isaac!

Through the years I probably haven't referenced the HPC much... definitely some... I have been using their projections a lot lately. Now... I'll share how the come to their determinations. This comes straight from their website!

HPC Mission

The Hydrometeorological Prediction Center (HPC) provides forecast, guidance, and analysis products and services to support the daily public forecasting activities of the NWS and its customers, and provides tailored support to other government agencies in emergency and special situations. 

We are here to assist and be a resource for you. We are available 24 hours a day, 7 days a week to alert you to the potential for significant weather events dealing with heavy rainfall or snowfall, to discuss quantitative precipitation forecasts and model differences relating to general weather and precipitation forecasts, and to provide forecast guidance into the medium range period (days 3 to 7). Most of the forecasters at the HPC have extensive experience at quantitative precipitation, heavy snow and medium range forecasting. 



Quantitative Precipitation Forecasts (QPFs)

Forecasters at the HPC [and its predecessor organizations, NMC's Meteorological Operations Division, Heavy Precipitation Branch (HPB) and the Quantitative Precipitation Branch (QPB)] have been issuing QPFs since 1960. All QPFs incorporate the latest surface and upper air analyses, radar data, satellite data, and model guidance from the NAM, NGM, GFS and RUC displayed on N-AWIPS workstations. HPC also works in conjunction with meteorologists in NESDIS's Synoptic Analysis Branch (SAB) to obtain information regarding satellite trends, precipitation and moisture availability estimates. This co-location and collaboration between SAB and HPC is bureaucratically known as the National Precipitation Prediction Unit (NPPU). 

A Senior Branch (lead) Forecaster (SBF) is on shift at all times. He or she is responsible for producing the day 1 24-hour precipitation forecasts, coordination of all HPC products (both internally and with other NWS offices), and center administrative operations after business hours. In addition to normal duties, the SBF participates in the East Coast winter storm and NHC hurricane conference calls regarding heavy precipitation, occasional unscheduled FEMA conference calls and numerous media interviews. 


The QPFs are what I have been sharing these past few days. The one issued this evening has me concerned. Let's take a look and you'll see why!

All I can say is WOW!!!! This is some pretty heavy stuff. With that being said... By the time this system gets here It could lose a lot of the moisture content and might just throw down a couple of inches... not what this graphic suggests. Isaac is going to go through a lot of changes between now and Sunday. The bulk of this is expected to begin falling by Sunday. The forward speed is slowing down quite a bit.. meaning... more rainfall is possible! That and the fact that it turns more towards the south once it gets into Kentucky! Another projection that has changed quite a bit these past few days.

Here's the GFS

This shows us very streaky 1-2" areas in KY. This seems more up to my speed. With everything that I have seen so far this week with Isaac and with everything I am seeing in the models I think 1"-3" seems more likely here in our region.

I am out on Friday... but I will be updating the blog as much as I possibly can! If the worst case scenario happens... I'll be at the station!!!

Updated Timing Isaac

Friday: Outer bands could ignite scattered showers & storms.

Saturday: Scattered showers & storms.

Sunday: Widespread rain arrives with potentially heavy amounts of rain.

Monday: More widespread rain.

Some of the storms that develop could even become strong or severe. Something else you will notice this weekend will be the very humid airmass here in east KY. Highs will only be in the low or maybe even mod 80s this weekend. But the humidity will be terrible. For those of you that have been to a beach somewhere and experienced the a shower while there... it will feel just like some beach... some where!

I'll have another update on Friday morning-afternoon!

I'll be back home in Magoffin County on Friday for the annual Founder's Day festival. I'll be hosting the Miss Magoffin County Pageant. Come check out some very talented contestants and other acts that will be performing in between!

C-Ya Bye


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