More Rain To Kick Off June

It looks like the rainy pattern that we have been in, is not going away anytime soon thanks to a near persistent trough of low pressure covering the eastern half of the nation. Although it will shift, and loose it’s grip on us from time to time, the overall result will lead to above normal rainfall and below normal temperatures. The following chart shows the 500 mb circulation around the northern hemisphere. The big L parked over the Great Lakes is the trough that is currently helping to bring us the unsettled weather of late.

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The forecast from the Climate Prediction Center points to this trend continuing as well. Both the 6-10 day, and 8-14 day forecasts call for below normal temperatures and above normal rainfall.

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The winner in all of this is the drought situation across north and central Georgia. Since the beginning of the year the percentage of the state that was under extreme drought has been reduced from 49.64% to 6.37% with absolutely zero extreme or exceptional drought showing up in north Georgia. February and March were not kind to us as far as rain is concerned. A combined 4.55″ in that stretch was woefully below normal. Since then we have made up ground with 5.75″ in April and 4.35″ so far this May!

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So even though it seems like we can’t get a break from the never ending showers and t-showers, it will be nice to be ahead of the game before the dog days of summer arrive.

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Recent Rain & The Drought

The recent rain from this past weekend will undoubtedly help with the drought conditions across north Georgia. Most locations saw between one and two inches of rain with two to three inches in isolated spots.

Leading into this past weekend forty six percent of the state was classified as being in a moderate drought, with thirty eight percent being abnormally dry.  Nine percent had severe drought with another three and a half percent in the extreme category.  None of the state was classified in the exceptional category, while almost three percent had no drought at all.

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Lots of heavy rain fell across the mountains where extreme drought remained as of last week. Hopefully when the new numbers are released tomorrow we will see that area of red (extreme drought) shrink!

COLD IS OUT, WARM IS IN

After the bitter cold that came in the wake of our first winter storm this past weekend, it now looks like a reversal of fortune is fast approaching. We could see temperatures a good 40 degrees warmer Thursday than they were on Saturday! Any snow north of Atlanta will sure to be gone by then.

Unfortunately another cold night is on the way with subfreezing temperatures across most, if not all, of north Georgia. There are many areas still dealing with ice and snow covered roads that will refreeze in the overnight hours as temperatures once again drop below freezing. This should be the last night this week, and possibly for a while, where temperatures this cold will develop.

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As we head through the day on Tuesday our winds will start to swing more to the south, helping the high temperatures to jump into the 50’s. Much of the nation will be warming as well, as a large ridge of high pressure begins to establish itself across the eastern half of the country.

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By Wednesday we are looking at highs in the 60’s, and by Thursday and Friday highs will climb to 70 or better. Not bad for a week that is starting out this cold.

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Usually when you get such a spike in temperatures this time of the year, you can always count severe weather not being to far behind. This time though that is not the case. In fact apart from a few showers north on Wednesday, our next chance for showers won’t arrive until sometime on Sunday!

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NOVEMBER AND SEVERE WEATHER

Just about every November here in the south we invariably see a round or two of severe weather from thunderstorms forming along strong cold fronts sweeping in from the north. It’s a time of the year similar to spring, where the atmosphere is in turmoil with the introduction of cold air from the north colliding with leftover warm air here in the south. Tornadoes and damaging winds are the main culprit during severe weather’s “Second Season”.  In fact last November 18th. tornadoes developed in Coweta, DeKalb and Fulton counties. Although they were small EF1 & EF0 tornadoes they still caused some minor damage.

Next week we could be dealing with one of those scenarios where a strong cold front, combined with a potent upper level system, collides with warm air already in place. The GFS model is hinting at a very strong vortex aloft sweeping in sometime next Thursday the 10th.

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This combined with a strong cold front at the surface could produce damaging thunderstorms from Mississippi to here in Georgia next Wednesday and Thursday. The 00z 6 hour precip depiction from the GFS Operational indicates a strong line of thunderstorms moving in next Thursday evening.

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Hopefully this will change, and we will come out with a gentler solution, but just in case we will be watching for the possibility of severe weather closely.

NOVEMBER TO START OFF WARM BUT WILL IT STAY THAT WAY?

One thing for sure is that November will start off well above normal with record highs possible during the first week. Highs this weekend will soar back into the low 80s, and those type of readings should stay with us at least through the following weekend. But will it last through the rest of the month? After all it is November, and it should be cooling off, right?

Well I decided to look back through the record books at previous Novembers going back to 2000. Of the previous 16 Novembers, 7 of them were above normal (2001, 2003, 2004, 2005, 2010, 2011, 2015). The warmest year was 2001 checking in with an average overall temperature of 59.9 compared to the normal of 54.0. From the graph below you can see that most of the month stayed above normal. It was very consistent.

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Many months started out very warm only to end up below normal in the end. 2000 is a perfect example where the month began very warm with a high of 80 on the 1st, and then back to back records of 81 on the 2nd and 3rd only to start a slide toward cooler temperatures. That month ended up with an overall average temperature of 51 compared to the normal of 54!

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You can see by the graph above how the first three days of 2000 started off much warmer than the rest. Along with the cooler weather that year it was also wetter than average with over 5 inches of rain recorded!

BELOW NORMAL TEMPERATURES?

Yes that’s right we have below normal temperatures in the forecast for this week, but what about next? The 6-10 day forecast indicates some relief for areas to our west but here in north Georgia it appears that we will see temperatures at or near normal.610temp.new

So don’t get too excited about the prospects of August all of a sudden becoming cooler than normal here is north Georgia. Rainfall could be a different story. It looks like the unsettled, rainy pattern developing this week could continue into next week as well bringing much needed rain to our area.814prcp.new (4)

Above normal rainfall would be a beautiful thing since much of the central and northern part of the state is either in severe to extreme drought.

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MILDER WEATHER RETURNS

As January draws to a close milder air will begin to arrive starting Thursday. Much of the southern half of the nation will see a significant warm up with temperatures locally climbing into the mid 50s! In the Mid-Atlantic states where they saw enormous snowfall totals a week ago, they will now see much of that melt as temperatures there rise into the 40s and eventually into the 50s this weekend. We have 60 degree readings to enjoy here both Saturday and Sunday.

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Shower chances are also in our future both later tonight (to the south and southeast),

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and on Monday out ahead of a stronger system that will be developing in Texas.

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As the storm system rapidly develops late Monday and Tuesday even warmer air will be drawn ou ahead of the storm pushing temperatures here well into the 60s to near 70.

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The bulk of the rain with the next, stronger system will arrive on Tuesday and into early Wednesday. With the warmer air in place a few t-storms may be possible.

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As the storm system pushes east, colder air will eventually move in from the northwest,

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eventually dropping our afternoon high temperatures across north Georgia into the 30s by next Friday.

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The cold air may stick around through the weekend of the February 6th & 7th, but conditions will be dry.

WEATHER HEADING INTO CHRISTMAS

With the warmer than normal start to December lots of people are wondering if the trend will last heading into Christmas. Here in the Southeast it looks like a pretty good bet that the pattern, for the most part, will hold together through the end of the month. All of this is in response to the strengthening El Nino in the Pacific. Take a look at the the 8-14 day temperature forecast that runs through December 21st.

8-14 day tempsThe entire Eastern two thirds of the nation is forecat to have above normal temperatures with the greatest certainty being across the Great Lakes and the Northeast! In fact Buffalo, NY has yet to see any snow which breaks the record for the latest date in the season without any measurable snowfall.

To go with above normal temperatures one would expect above normal rainfall during El Nino episodes such as this, and that is exactly what is forecast. So far we have yet to see much rain materialize this December, but a few strong storm systems are poised to moved through. One especially on the way this Sunday could bring some locally heavy showers and t-showers.

8-14 day precipTaking a look at the 500 mb flow through the next several weeks, it appears that the trend will be to keep the ridge in the east and the trough in the west. The only exception will be the occasional trough slipping through quickly limiting our chance for any extended periods of rain.

500mb 1500mb 2So all in all I think would be safe to say that the month of December will turn out to be much warmer than normal. As for precipitation our chance for seeing any snow is about as low as it gets, but with the warm air in place we do need to watch for the possibility of severe t-storms with the passage of these quick moving systems between now and the end of the month.

MINI SEVERE WEATHER SEASON, EL NINO & WINTER

Each year around this time we notice an uptick in the number of tornadoes across the Southeast and here in Georgia. November and for that matter December have been come to be known as the Second Season for severe weather after the lull that is seen during the summer and early fall.

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The atmosphere at this time of year (just like in the spring) is going through a major transition as cold air starts to shift southward. Unfortunately the warm air hasn’t completely gone away and this leads to problems. Then if we are in an El Nino year you have to throw in a very active and powerful branch of the southern Jetstream which you would think would help to produce lots of severe weather and tornadoes. But is that really the case? Is there a correlation?

This year’s El Nino is on track to rival the last major episode that took place in 1997-1998. Since then there have been two moderate episodes (2002-2003 & 2009 & 2010) and two weak episodes (2004-2005 & 2006-2007).

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Going back and comparing the El Nino episodes with tornado activity doesn’t reveal a clear picture. In fact during the strongest El Nino (1997-1998) there were only two tornadoes in November and none in December. The one episode that yielded the greatest number was the 2002-2003 moderate El Nino. November and December of 2002 saw 12 and 13 tornadoes respectively! The other El Nino episodes resulted in the following number of tornadoes: 2004-2005 (0 in November and 0 in December); 2006-2007 (2 in November and 2 in December); 2009-2010 (0 in November and 8 in December).

So is there a correlation between El Nino and fall tornadoes. It appears not. Is there a correlation between El Nino and wetter, cooler weather in the months of November and December? Absolutely! In fact looking back at the last five El Nino episodes and the ten corresponding months of November and December, there have only been two drier than normal months (Nov. 1997 & Dec. 2006) and two warmer than normal months (Nov. 2004 & Dec. 2006).

With all of this being said where are we so far this November? As of today Georgia has seen 2 tornadoes. They occurred at the beginning of the month in Telfair County in south Georgia. There is a possibility that a few more could occur this Wednesday primarily in the southern tier of the state. Rain so far this month has been abundant. Here in Atlanta we have recorded 6.94″ which as today is 5.05″ above normal. The normal rain total for the entire month of November is just 4.10″! In keeping with the strong El Nino you would expect the temperatures to be slightly below normal, but that has not been the case. In fact as of today we are 3 degrees above average so far this November.

So what should we expect going down the road through the winter? All indications are for the El Nino to stay strong if not strengthen some. Therefore expect cooler than normal temperatures

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and above normal precipitation.

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What about snow? Below normal temperatures and above normal precipitation…..sounds promising for snow. Right? Wrong! The below normal temperatures are factoring in the increase amount of cloud cover that comes along with an increase in storm systems rolling through. Actually in El Nino years we often have a wedge type setup with cold air sliding in out of the Carolinas at the surface in advance of the storms coming in from the west. This in fact is more conducive to ice events than snow. I personally would rather have the snow!!! As they say stay tuned, I’m sure it will be an interesting if not memorable winter!

FALL FORECAST

Fall is just about here and officially arrives at 4:22 am Wednesday morning September 23rd. So what can we expect as we head into October, November and December? Rain has been hard to come by since August, and many spots across north and central Georgia are entering certain stages of drought. The hardest hit areas are from Macon to Augusta with severe drought showing up just south of Augusta. Abnormally dry conditions have increase the most from just under 6% of the state at the beginning of the year to 42% currently.

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Rain totals here in Atlanta have fallen off in September after a wet summer that saw above normal rainfall for June and August, and near normal rainfall in July.

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As we head into October there is a very good chance that the dry pattern that has established itself so far this September will continue.

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Warmer than normal temperatures are also expected for October which combined with the dry conditions would further elevate the drought conditions across the state. This could all be changed by a few late season tropical systems, but with a moderate to strong El Nino firmly in place that scenario is not likely.

Our prospects for alleviating the drought start to look better as we enter November and December. Above normal rainfall is expected for the period of October through December along with near normal temperatures.

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All indications point to the El Nino lasting into next spring, and historically this leads to a wetter than normal winter period. Therefore if for some reason we end up with a drier than normal fall, we should be able to pick up the slack over the winter months. As for temperatures they typically run slightly below normal, not because of Arctic outbreaks but because of a more active southern branch to the Jetstream that leads to more clouds and rain.