The weather pattern has become more active as we head into April, regrettably though, the west continues to miss out on rain opportunities as it has most of March. Because of this, dryness and drought are gradually overtaking this area. Springtime severe weather chances will be present for the western district N & W of KC Wednesday and for a majority of the eastern district on Thursday. Hail and damaging straight line winds will be the main threat. Here’s a look at the map for the midweek severe weather chance:
The latest outlook actually has backed off the elevated risk to well west of Kansas City Wednesday and Wednesday evening. Storms in the Central Plains Wednesday should rapidly fade as they drop southeast Wednesday night, weakening rapidly by the time they reach KC and it’s not out of the question much of the west could receive very little precipitation. Storms then re-fire mid day Thursday, peaking over SE parts of STL as well as SEMO/SW IL Thursday evening. Averaging most of the overnight model data brings totals similar to this:
Generally less than half an inch for much of the southern part of the KC area, 1/2 to 1″ for the north (where the storms will be stronger). STL/SEMO/SW IL continue to have impressive rains with totals of at least 1/2 fairly widespread and 1-1.5″ totals SE of the STL area.
The high resolution NAM model is considerably more generous with it’s totals, bringing rains to the KC area around 2-5AM Thursday morning and then on to STL/SEMO/SW IL by lunchtime.
It leaves behind generous rains for KC (1-2″), 1″ for SEMO/SW IL and leaves STL with totals 1/3 to 1/2″.
This may be very generous as the lower resolution version has 1/2 to 1/3 of these totals for KC. The GFS/EC models both blanket the entire region with around 1″ of rain, although the placement of the axis of heaviest rains vary from place to place. This is typical in the warmer season when rains come from thunderstorm clusters rather than large scale low pressure areas. It all depends upon where/when the clusters form and how they track. Dissipating severe storms can be very heavy rain producers, so it won’t be surprising for some areas to check in with several inches. The question is–will those areas needing it most get it?
Additional weather systems through the next week double those totals over the east, while strongly suggesting those areas in the west that miss this opportunity will continue to wait (at least a week more) for much needed moisture.
April is really the beginning of the wet season in the western district, with April through October average monthly totals of 3-5″+, so deficits in these next few months are very hard (and as we’ve seen several times this decade – almost impossible) to make up. There is a much more pronounced difference between wet season average monthly rains and dry season range (4″).
The eastern district has an earlier wet season beginning in March, peaking in May and then declining into August with a more uniform range from month to month all year, generally within 2-3″.
March ends today and it was a very dry month for the west. Take a look at these graphics (click to make them more readable). They show the observed March rain, the average March rain, departure (or difference) from average and the percent of average. Note how the west only had 25-50% of average rains while the east ranged from slightly dry NW to very wet SE.
This has left a good part of the Plains in developing drought. Drought has persisted in the KS/OK area for most of the 2010s so far.
The latest monthly drought outlook from the CPC expects drought development/intensification to connect the ongoing drought over the Upper Midwest with that in the Southern and Central Plains.
This is based upon the latest climate outlook for April from the CPC. The original CPC outlook issued mid month had no strong signal for warmer/cooler wetter/drier conditions for April, 2015. The original drought outlook for April indicated a retraction southwest and south in drought conditions away from the western district. The update issued today shows a weak signal for below average rain in April (from just NW of KC northwestward) and above average temperatures regionwide. Due to this, expects drought conditions to hold near or just W/S of the western district next month. The CPC drought outlook has been a little optimistic, though, for several months in a row compared to what’s actually happened. The eastern district, looks to continue with a weak signal for above average rains April.
Week in Review:
The last week has been cooler with warmth from mid country west, greatest over the Southwest. The core of the cool has been centered from the Midwest through the Great Lakes to the Northeast.
Several rain-producing systems moved through bringing rains to areas N of KC and the first Severe Thunderstorm Watch of the year to the east. It was also cold enough for a small area of light snows to slide south through Mid Missouri generally between the forecast districts.
The rain and severe weather was fueled by a strong contrast in temperatures. Warm 60s and 70s were over SE KS/SW MO while chilly east winds and temps in the 30s and 40s lingered over the KC area.
Parts of SEMO/SW IL dipped back into the frost/freeze range with lows in the 20s to lower 30s on the morning of the 28th.
In the southern Hemisphere, TC Nathan’s remnants finally dissipated northwest of Australia, with no new systems forming. A very strong Typhoon (Super Typhoon Maysak 04W) formed in the western North Pacific over the weekend:
Maysak was located well southwest of Guam and very near the Island of Yap. The NW Pacific is a basin where tropical cyclones can and do form every month of the year, although the peak is in the late summer and fall. Another system was brewing further west and just north of the Equator and may become the next tropical system in the NW Pacific.