October 1, 2010: A look back at September and a look ahead to October

October 1, 2010:

Dry weather to continue for the next 8-10 days.  Look for an increased rain/storm threat as we head towards October 15th-18th time frame.

Your seven day forecast can be viewed by clicking here.

Can you believe that October has arrived?  Seems like we were just entering September!  We are now one month into our fall forecast (remember the fall forecast covers September 1st through November 30th).

The call for the three month period was for odds to favor above normal temperatures and below normal precipitation with the wild card being a tropical system.  In the event of a tropical system we would see the potential for significant rainfall (although my specific forecast for Hermine was off a bit - I expected the heaviest rainfall to fall several counties north and northwest of where it actually fell - I was not happy with that particular forecast and did not catch on to the more southerly movement until 6-12 hours before the event).

So - with that in mind - let's take a look at how the September numbers ended up.  I am going to post the official numbers from (west to east) Poplar Bluff, Cape Girardeau, Carbondale, Paducah, Evansville, and Owensboro (all data provided by the Paducah, Kentucky - National Weather Service Office)

Poplar Bluff, Missouri
Average temperature for the month of September = 71.5 which was +0.7 degrees above normal
Precipitation for the month of September = 5.81" which was +2.44 inches above normal

Cape Girardeau, Missouri
Average temperature for the month of September = 70.4 degrees which was +0.9 degrees above normal
Precipitation for the month of September = 5.42" which was above normal (number is missing)

Carbondale, Illinois
Average temperature for the month of September = 69.4 degrees which was +1.9 degrees above normal
Precipitation for the month of September = 1.52" which was -1.61" below normal

Paducah, Kentucky
Average temperature for the month of September = 72.3 degrees which was +3.2 degrees above normal
Precipitation for the month of September = 3.64" which was +0.08" above normal

Evansville, Indiana
Average temperature for the month of September = 72.1 degrees which was +3.0 degrees above normal
Precipitation for the month of September = 0.36" which was -2.73" below normal

Owensboro, Kentucky
Average temperature for the month of September = 72.8 degrees which was +1.9 degrees above normal
Precipitation for the month of September = 0.76" = which was -2.75" below normal

The remnants of Tropical Storm Hermine brought heavy rainfall to portions of our region (note the extreme differences in rainfall from west to east over our region).  Rainfall totals of 1-5" were reported across portions of Arkansas, Missouri, Illinois, Kentucky, and Tennessee.  I recorded nearly 4.5" of rain here at the Weather Observatory from the tropical system.  Portions of our region, however, received almost no rainfall from Hermine.  It was once again feast or famine. 

Here are some rainfall maps from September 8th-10th (Tropical Storm Hermine).  The maps indicate how much rain fell during those days.  Click on the image for a closer look at rainfall totals.
















September 8th rainfall - Hermine moving in from the southwest















September 9th - Hermine moves into Oklahoma.  Heavy rainfall spreading north and northeast.















September 10th - heavy rain spreads into portions of our local region. 

So, overall the month of September was extremely warm.  Rainfall was much below normal over portions of our region and normal to above normal in areas that received the remnants of Tropical Storm Hermine.

Let's take a look at some more maps from the past month

The map below indicates just how dry it was over parts of the U.S. - this is the departure from normal precipitation map.  Yellow areas are below normal.  Click image for larger view.



















The map below shows the departure from normal temperatures.  Much of the U.S. was above normal in the temperature departure.  Including our entire region.  Click map for larger view.



















Zooming in on our region - departure from normal temperatures (below).  You can see just how extreme it was.  A warm September!





















And one more map (below) - this map indicates the percent of normal precipitation that fell over our region.  You can see the extremes.  This is because of the remnants of Tropical Storm Hermine.  It was feast or famine for our local counties!  Click map below for larger view.





















Looking ahead to October

Temperatures will average normal to below normal over our region for the next 7 days.  Nighttime lows are expected to be well below normal this weekend.  Strong systems along the east coast will help filter in cooler air from Canada into our region.  We may even see some upper 30s and lower 40s for overnight lows in the coming days!  The next 8-10 days will bring below normal precipitation. The drought will continue to worsen.  Unfortunately. 

The latest (September 30th) drought monitor map (below) shows the spreading drought across our region.  You can read more about the drought and click on local maps by clicking here.  Click on the map for a larger view.






















The official October outlook from NOAA - click maps (below) for larger view of the image
























Temperature outlook from NOAA (above) - indicates that the odds favor above normal temperatures - overall.  That does not mean we won't see some cold weather. 

The precipitation outlook from NOAA (below) - the map indicates that the odds favor below normal precipitation (remember that the wild card in this forecast would be tropical systems)


























Fire departments are asking that the public use caution when burning grass, fields, or debris (or refrain from burning all together). 

We are entering the windy season (the last week has brought several periods of winds above 30 mph).  The stronger winds of the fall season will also increase the risk for brush and field fires.

Overall October might end up normal in the temperature department.  There are indications that the middle to end of October will bring warmer conditions.  So if the first part of the month is below normal and then the last part of the month is above normal - well that might end up averaging out to near normal. 

We normally start to see a more active storm track as we enter the middle and end of fall.  I suspect that late October and November will bring several severe weather events.  This is not uncommon for our region.  This year will likely be no different.  The NWS reminds everyone that our region normally experiences a second peak in severe weather during the fall months.  You can read more about this subject on the Paducah, National Weather Service web-site.

My previous fall and winter thoughts remain unchanged.  The overall pattern for the three month period (September through November) will favor above normal temperatures and below normal precipitation.  The storm track will become more active as we move further into the fall months.  An eventful winter is forecast - meaning wild swings in both temperature and weather conditions.  My previous thoughts can be read by clicking here.

La Nina is likely going to play a big part in the upcoming winter - especially if we see a neutral to positive NAO (I discussed this more extensively in my fall outlook - see link above).  Just check out these maps comparing last year with this year (Pacific Ocean water temperatures are what we are looking at).  These maps were posted by Brett Anderson on his blog, as well.  Click the images for a closer look.
















Last year we experienced an El Nino (note the yellow/orange colors over the Pacific Ocean).  Those colors indicated above normal water temperatures. 
















This year's water temperatures.  Note the dramatic changes in the Pacific.  Below normal temperatures over a wide/large area.


- Meteorologist Beau Dodson
McCracken County Office of Emergency Management

For the latest watches and warnings please visit your local National Weather Service Office http://www.weather.gov/organization.php

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