Change is Coming!

Tired of the heat?  Desperate for rain?  Have we got some news for you!  Beginning tomorrow, an unusually powerful upper-level low will retrograde - that is, move from east to west - towards the Southwest part of the nation from the Northeast.  We know that weather patterns tend to move from west to east in the Northern Hemisphere, so while one that moves from east to west is not unheard of, it is certainly not common, especially this time of year.  This low is expected to track right through the middle of the state, bringing central Oklahoma the most drastic changes.  High temperature drops of near 20 degrees and a healthy amount of rainfall can be expected starting Sunday and lasting through mid-week, especially for central and western Oklahoma.  But, of course, today we must deal with our last day of heat.

High temperatures will continue to be a scorcher today, with no rain in sight until after midnight.  Skies will be mainly sunny for all of the state this afternoon.  Expect the low-to-mid-100s for highs across western Oklahoma and the mid-to-upper-90s for highs across central and eastern Oklahoma.  Heat indices will be near 100 degrees across parts of central and eastern Oklahoma.  A south to southeast wind will blow between 5 and 15 mph.  Gusts, prevalent mainly in central and western Oklahoma, may reach 25 mph.

Now...what we hope you've been waiting for.  Beginning tonight after midnight, we have up to a 50% chance of showers and thunderstorms for central Oklahoma and about a 30% chance of showers and thunderstorms for eastern Oklahoma as the upper-level low begins its arrival.  The chance for rain increases to as much as 70% throughout the day on Sunday for central Oklahoma, 40% for eastern Oklahoma, and 50 to 60% for western Oklahoma.  Eastern and western Oklahoma will see the best chance for rain starting in the afternoon.  For central Oklahoma, Sunday will be a rather dreary day as rain beginning in the early morning will be off and on throughout the entire day and into the night.  Skies will also be cloudy.  Across eastern Oklahoma, skies will be cloudy throughout the day as well.  For western Oklahoma, skies may be partly cloudy to start off the morning but will become cloudy by the afternoon.

Rainfall will be accompanied by significantly cooler temperatures.  As central Oklahoma sees the highest chance for rainfall, the region will also see the coolest temperatures.  While morning lows will continue to be rather mild across the state, that is, in the upper-60s to low-70s, afternoon highs will be another story.  Sunday will be more reminiscent of spring or fall than summer in central Oklahoma, with highs only reaching the mid-to-upper-70s!  In fact, Oklahoma City is expected to see a 20-degree high temperature drop from Saturday to Sunday!  The rest of the state will also see much cooler temperatures topping out no higher than the upper-80s.  The warmest highs will occur across northeast and southeast Oklahoma as well as the panhandle.

For Sunday overnight and Monday morning, the persistent rain in central Oklahoma will continue, with chances as high as 60%.  Western Oklahoma will also see rain chances as high as 40%, especially the southwest.  This is certainly good news as parts of southwest Oklahoma are in an extreme to exceptional drought.  Throughout the day on Monday, eastern Oklahoma will see as high as a 50% chance of rain, central Oklahoma will see as high as a 60% chance of rain, and western Oklahoma will see as high as a 70% chance of rain.  Skies will be mainly cloudy all across the state.

Monday morning lows will be in the low-60s across western Oklahoma and the mid-to-upper-60s elsewhere.  Monday's highs will continue to be unusually cool, especially for the central and western parts of the state.  Highs in western Oklahoma will only reach the upper-70s, and this includes the panhandle.  Highs in central Oklahoma will reach the low-80s.  Highs in eastern Oklahoma will reach the mid-to-upper-80s, but 90s are still out of the forecast for Monday.

For Monday overnight and Tuesday morning, rain chances decrease to about 20 to 40% for all of the state.  This will also be the case throughout the day on Tuesday and into Tuesday evening.  The best chances for rain on Tuesday will be in western Oklahoma as the upper-level low moves farther towards the west.  Tuesday's highs will begin to rebound somewhat to the low-to-mid-80s across western Oklahoma, the mid-80s across central Oklahoma, and the upper-80s to low-90s across eastern Oklahoma.

Lingering showers and thunderstorms may remain across the state through Wednesday and Thursday, but chances are no greater than 20% at this time.  Highs will begin to be on rise back to normal, with the mid-90s expected across all of the state on Friday.  Skies will also become sunny once again.

Please note that a healthy amount of rainfall is expected to come with this weather system.  Currently, the Weather Prediction Center is forecasting the highest amounts in central Oklahoma at over 4 inches, with surrounding areas receiving between 1 and 2 inches.  These rainfall totals are valid from today through 7 PM Friday.  The exact track of the low may change these rainfall totals.  Additionally, due to the high amount of rain in a short period of time, flooding will become a concern.  Please take extra precaution in your daily commutes this week.



Sources: NWS, WPC, HOOT