Ticker for May 22, 2012

                
MESONET TICKER ... MESONET TICKER ... MESONET TICKER ... MESONET TICKER ...
May 22, 2012       May 22, 2012       May 22, 2012       May 22, 2012


Hey, it rained! Hey, it got drier! What?

Before we begin with the moisture, let's talk tornadoes. One of the consequences
of our dry (more on that in a bit) May thus far is a lack of tornadoes. There
just haven't been enough of the right ingredients with May's storms to get
tornadic supercells. The result is one of our quietest Mays on record (since
1950, when accurate statistics begin) as far as tornadoes go. According to Doug
Speheger, the Ayatollah of Twister-ola, at the Norman NWS office, we have only
recorded two tornadoes for this May thus far -- an EF1 twister in Nowata County
and a more powerful EF2 tornado in Craig County. Both of those tornadoes
occurred very early on May 1, so we're close to having no tornadoes for the
month. The preliminary count for the year is now up to 50 tornadoes, so just
a few shy of our average annual total of 55. Here are the least active tornado
months of May since 1950. Notice that three of the top six quietest have
occurred since 2004.

-****-
Year 	May Tornadoes
2005	      0
1988	      2
2012          2 (May 1-22)
1958	      4
1967	      4
2006	      4
2009	      4
-***-
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With dry conditions gaining momentum across the state over the last month or so,
the weekend's rain was a nice gift. Parts of west central and central Oklahoma
received a nice drink of water from the storm system. Our Mesonet sites in
Grady County in particular recorded totals of more than 3 inches. Radar estimates
show those more robust totals extended farther to the west as well, although a
bit more localized.



The Mesonet site at Ninnekah totaled 3.89 inches and Chickasha was close behind
with 3.43 inches. Other than that corner of the state, however, the rain either
missed its mark or was much lighter. Our primary rainy season runs from April
through about mid-June. With more than half of that period gone, this rainy
season has been a bust for much of the state. According to data from the Mesonet,
this May is still on track to be one of, if not THE, driest on record. The
statewide average is now 1.19 inches, 2.45 inches below normal for the May 1-22
period. The driest May on record was back in 1988 at 1.3 inches. It's been
the driest May 1-22 period on record for north central Oklahoma at only 4%
of normal. That same period for the Panhandle and the northeast regions of the
state rank as the third- and second-driest on record, respectively.

There are still several Mesonet sites up in the northern sections of the state
yet to register any moisture for the month. Now I'm not sure which higher
power Grady County asked for help (I'm betting the upstairs variety), but
whatever they did, it definitely worked! It's the one area of the state that
has had above normal rainfall during May.




Going back to the beginning of April (and the beginning of our primary rainy
season), we can see those areas of the state that have had too much ... and those
that have had too little. Some areas in eastern Oklahoma are in the 20-40% of
normal range. North central Oklahoma, especially in Grant and Kay Counties,
are still in the 160%+ range due to those flooding rains at the end of April.




Now the problem we're talking about here is not a major one, at least not yet.
But we once again face a week or so of windy, warmer-than-normal weather. That
type of weather will continue to sap our soil moisture, as well as diminish
reservoir/farm pond levels. During this time of year, with the energy from the
sun increasing each day, the stress on that stored moisture increases quite
rapidly. That is occurring now, as evidenced by this 7-day change in 10-inch
soil moisture as measured by the Mesonet.



The areas that are drying out, both due to evaporation and transpiration (from
all the accelerated vegetation growth) are becoming quite evident (brown = dry,
green = wet).




The real worry is that this dry pattern will extend uninterrupted into through
more of the rainiest part of the calendar. The 6-10 and 8-14 day outlooks from
the NWS' Climate Prediction Center are now showing increased odds for drier
and warmer weather from the end of May through the first bit of June.

6-10 day outlook (May 27-31)



8-14 day outlook (May 29-June 4)



Those outlooks do not say that it will be completely dry across the state for
that period. Just that the odds are increased that it will be drier (and warmer)
than normal. There is talk of another storm system early next week, so another
dose of rain would be nice. Enough to squelch our burgeoning dry conditions?
Too far out to determine that just yet.

Summer is just around the corner. I'll give the same caution I gave last year:
you do not want to enter the summer in Oklahoma with drought either building or
already in place. The odds are not in your favor if that occurs.

Gary McManus
Associate State Climatologist
Oklahoma Climatological Survey
(405) 325-2253
gmcmanus@mesonet.org