Wet May will give way to humidity and summerlike temperatures as we enter June


After a very active May, the weather pattern slows down and warms up as we enter June.  Cloudy grey skies over the weekend will clear on Monday and we’ll start on a cool note, before temperatures and the humidity  rise mid week and beyond.  Be sure the A/C is working as we’re going to be needing it after Wednesday.  Highs in the low-mid 80s and lows in the 65-70 degree range are expected. Rain chances will be much more scattered, and they will be tied to thunderstorm clusters which form on the Front Range each afternoon and track east and southeast each night.  Right now, that train of storm clusters is likely to run from MT/WY/CO through the Dakotas into NE/MN and IA, but these may trend a little further south than forecast right now.  This will be one of those typical mid summer patterns where these clusters roll off the high terrain in the evening and whatever’s left over approaches or passes through overnight or in the morning.  That’s more likely for us late in the week, while early in the week, we will likely see periods of high clouds (blowoff from the distant storms) mainly each morning and early afternoon, so 100% sunny days all week are not anticipated either, but at least we’ll have at least the first half of the week rain-free.  No organized or major severe weather outbreaks are anticipated either, as those will be mainly near where the storms form along the front range.  Late this week there will be the potential for some of the clusters to give us some gusty winds if they remain strong enough as they reach our area.


May in Review:

Most notable for May was the rainfall.  The western district had 7-11″ of rain, with Kansas City International reporting the sixth wettest May on record with 10.25″ of rainfall.  10.29″ marked the 5th wettest May in 1996.  Additionally, there has not been 10″ of rain reported at KCI since June, 2005, which was just one month shy of 10 years ago. This puts KCI just under 3″ above average for 2015 and over 5″ above average for May.


The rain in the western district was the northernmost tip of a heavy rain area which extended and expanded SSW:

2015-05-31-1005-SCUS-MAY-PRECIP 2015-05-31-1005-COUS-MAY-PRECIP

10-20″+ fell over OK/TX making news with devastating flooding.

The eastern district saw significant rainfall as well, especially SEMO/SW IL, but STL finished the month nearly 1″ below average and is now nearly 1″ below average for 2015.


This series of maps (click to make more readable) show average May rains (L), percent of average observed rains (M) and difference from average observed rains (R).


This extraordinary rainfall has pretty well wiped out the multi-year central and southern Plains drought.  Lingering dryness is spotty over TX/KS/OK.



But this is a big difference when compared with 1 year ago:


This map shows the change from this time in 2014.  Yellows/oranges show worse-off locations while greens show improvement.


Wet areas this month stayed cool with drier areas seeing warmth this month.


The US NWS CPC expects higher probabilities for a cooler than average June centered on the south central Plains, with a ring of warmth from the west, through the north and along the east coast.  The cooler than average weather is in part due to the fact of this being very wet ground and a lot of the sun’s energy will go into evaporation rather than heating even without additional heavy rains.


While a signal for wetness remains across the Southern Plains, the stronger signal shifts northward to the CO/NE area and along the southern and eastern coasts.  Locally, this forecast shows little signal for wet or dry.  Other forecasts are for more widespread wetter conditions.  June rains are largely dependent upon where storm clusters form and track and as we’ve seen, some areas can be inundated while other areas not that far away miss out.

Global Tropics:

Western Pacific:

Super Typhoon Dolphin

Dolphin developed at low latitudes and was most notable for passing just north of Guam. This image was taken several days after the system had passed through the Marianas Islands (Guam is the larger island to the southeast of the eye.  The system was near peak intensity in this image.


TY Dolphin passed through the range of the Guam Radar with these series of images taken (Click to make more readable). The B&W image shows the subtle structure of the rain bands while the 3-D images also show some of the structure.  The red/blue image shows the wind field (speed) with blues winds blowing inbound and red winds outbound.

20150515_0844_PGUA_07WDOLPHIN_95kts-952mb-125N-1497E_100pc 20150515_0847_PGUA_07WDOLPHIN_95kts-952mb-125N-1497E_100pc 20150515_0850_PGUA_07WDOLPHIN_95kts-952mb-125N-1497E_100pc 20150515_0851_PGUA_07WDOLPHIN_95kts-952mb-125N-1497E_100pc 20150515_0856_PGUA_07WDOLPHIN_95kts-952mb-125N-1497E_100pc


Eastern Pacific:

Hurricane Andres (01E)

Andres wasted no time forming from a tropical wave along 100W south of Mexico at the end of May (the East Pacific season opens 5/15).  This series shows the system as it organized and neared peak.  As with most eastern Pacific tropical cyclones, the system moved well offshore and well away from any land areas.  As the month ended, it was approaching colder waters and will rapidly weaken the first week of June.

20150527_1745_goes13_x_vis2km_92EINVEST_25kts-1007mb-89N-1048W_100pc 20150529_1931_goes15_x_vis2km_01EANDRES_60kts-994mb-123N-1144W_88pc 20150531_1900_goes15_x_vis1km_high_01EANDRES_105kts-955mb-153N-1185W_100pc

Tropical Low 93E formed right behind Andres and was visible as a tight swirl of clouds.  Wind shear from Andres was preventing development, but as that system weakens, this one will strengthen and according to the NHC is likely to become a tropical depression early  this week, as a Tropical Storm, it would be named “Blanca”.  This looks to be a very busy tropical cyclone season in the central and eastern Pacific.


We’ll follow up with the progress of these two systems in later posts.


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