Category Archives: 10-day

Sunday Morning Rambles: Focusing On Severe Weather…

Low clouds and areas of fog will be slow to burn off this morning, but the sunshine should eventually return later this afternoon and evening, providing a phenomenal close to the weekend.

Despite the lack of sunshine this morning, temperatures continue to run much milder than average.  We’re currently running nearly 20° above where we should be at the 9a hour.

A quiet start to the work week is ahead as high pressure dominates early on.  That said, a weak storm system will scoot through the state Monday night and Tuesday morning and this will help offer up the chance of showers and perhaps a rumble of thunder.

The next (more significant) storm system will pose a severe weather risk to close the week.  We continue to keep a close eye on Friday and the Storm Prediction Center is as well, with western IL, IN, and western KY in their Day 6 Outlook.  It’s still early, but the primary focus with the severe potential this storm may pose will be large hail and damaging straight line winds.  Stay tuned as we continue to analyze the latest data.

We’ll turn sharply colder Friday night and Saturday.  Though it’ll feel much colder, we’ll really only “chill” to seasonal levels, including a gusty northwesterly breeze Saturday.

Longer-term, we’re rumbling into a much more active weather pattern through the mid range period.  As the mean trough sets-up position in the west, the ridge will flex it’s muscle across the east yet again during early portions of Week 2.  This will set the stage for a repeat of what we deal with Friday and, accordingly, we’ll have to monitor early next week for portions of severe weather yet again.

No Comments 10-day, Forecast Discussion, Forecast Models, Hail, Rain, Severe Weather, Spring Tease, T-storms, Unseasonably Warm, Weather Rambles

February Tug Of War…

With data only encompassing the first couple days of the month, February has gotten off to a warm start.  As we know, the trend over the past 24 hours has been colder and this will continue as we open up the weekend.

conus_mtd_t2max_anom_2017However the cold air won’t last and milder times will return by the second half of the weekend.  This back and forth “tug of war” type regime will remain as cold and warmth (relative to average) continue to battle over the upcoming couple weeks.  The latest European ensemble shows this nicely.

EPS2317This also favors a rather active pattern and confidence is high on a wetter than average period upcoming over the next couple weeks.  See the GFS ensembles support this idea.  A couple strong storms are also possible Tuesday.

gfs-ens_apcpna_us_4Unfortunately for snow lovers, the majority of significant moisture should fall as rain.  Best snow chances appear to come with “backlash” wrap around snow showers and squalls Tuesday night into Wednesday morning.  Accumulating snow is possible, but most amounts should be light.  We’ll keep an eye on it.

gfs_ptype_slp_conus2_19Longer-term, the fight continues deeper into the month.  As mentioned this morning, teleconnections and analogs would suggest cold and wintry conditions, but modeling sure isn’t going in that direction as of yet.  The battle rages on and given the trends of the winter, it’s hard to bet against the warmer solutions, albeit with lower confidence than we’d like to have from this distance.

No Comments 10-day, Arctic Cold, European Model, Forecast Discussion, GFS, Heavy Rain, snow, Unseasonably Cool Weather, Unseasonably Warm, Windy

Times Are Changing, Or Are They?

January-to-date is running milder than normal across the region- to the tune of 3.3 degrees (F).  This is after a frigid open to the month, as you recall.

conus_mtd_t2max_anom_2017The second week of the month warmed significantly and continues, overall, for the next week.

ncep_cfsr_noram_t2m_week_anomThe mid-January warmth is attributed to a roaring PAC jet which is currently helping flood the country with temperatures much more like spring than the dead of winter.  We continue to forecast 60+ this weekend across central IN.

Winter lovers, have no fear as changes appear to be in the offing as we go through the last few days of January and head into February.  The winter so far has featured conflicting signals that continue to try and compete with one another to take hold of the pattern.  Can we get these drivers to align in a way that would pull a more persistent trough into the east for the second half of the winter and, ultimately, set-up a sustained cold pattern helping make up for lost time in the snowfall department?  Time will tell, but we do note the following late month:

  • (+) PNA pattern
  • Sudden stratospheric warming event
  • High latitude blocking

All are encouraging for a shift back towards a wintry regime.  As always, the devil is in the details and we’re skeptical as to the longevity of these signals.  “Cautiously optimistic” would be the way to sum up our current feel longer-term into the month of February, but we’re not as bullish on lock and hold cold, wintry conditions at this time as what you may hear from some of our national compadres.  Understanding that various drivers can have a different impact mid and late winter as opposed to early is one thing.  It’s also important to note that long term modeling has been abysmal as of late and we want to tread through the next couple of weeks with caution to see whether or not the cold drivers can finally take hold.

Needless to say, at least through late month, one can see the significant changes take place at 500mb.

Thursday:

ecm_eps_z500a_noram_2This Weekend:

ecm_eps_z500a_noram_5Next Thursday:

ecm_eps_z500a_noram_9Next Weekend:

ecm_eps_z500a_noram_11The pattern begins in the short-term with a look that will power anomalous warmth through the weekend, along with renewed rain chances Thursday night into Friday (another 1″+ for most), but begins to shift next week towards the colder look.  The 2nd (weekend) storm system will be significant and poses a severe risk to the southeast region.  Modeling has backed away on the heavy rain threat Sunday, but showers will be around early next week along with very windy conditions (40+ MPH gusts).  Blocking is forcing the low south.  By the time we get to next weekend, the pattern has done a 180 and in a position to drill unseasonably cold air back into the central and eastern portions of the country.

As far as storms go later in the period, it’s far too early to discuss specifics, but the pattern seems to be one that will promote the chance to get into the act on high-ratio producing clippers.  It’s the first time we can say that this year.  Time will tell…

No Comments 10-day, Arctic Cold, Forecast Discussion, Forecast Models, Heavy Rain, High-latitude Blocking, PNA, snow, Spring Tease, Unseasonably Cool Weather, Unseasonably Warm, Windy

Shift Back To A Cold Pattern Awaits; What About Winter Storm Potential?

December-to-date is running colder than normal (to the tune of 2.2 degrees at IND), but the past (7) days has seen a flip in the frigid 1st half of the month.

December temperature anomalies, courtesy of Weatherbell.com.
December temperature anomalies, courtesy of Weatherbell.com.
Temperature anomalies the last 7 days. Courtesy of Weatherbell.com.
Temperature anomalies the last 7 days. Courtesy of Weatherbell.com.

The “relaxation” is temporary.  Modeling continues to advertise the recent “thaw” will give way to increasingly bitter times as we get deeper into the New Year.  By New Year’s Day we note the positive heights continuing to establish themselves across Alaska and Greenland (cold and stormy signal).  We also note the southeast ridge present, though to a lesser degree than over the past week.

jan1By Day (10), the cold pattern is well established over the Lower 48.  This is a coast-to-coast cold signal (heart of the cold centered over the west and central) depicted by the European ensemble, along with other modeling.

day10

ecmwf-ens_t850amean_namer_6Teleconnections support a cold pattern returning.

epowpo122916

aonao122916

pnaThe agreement amongst teleconnections is nice to see and ups confidence in the overall direction of where this pattern is heading in regards to colder than average times looming.  The negative PNA correlates nicely with the SE ridge that continues to make itself heard from time to time over the next few weeks.  It should also be noted that the phases of the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) become more of a factor for mid and late winter.

As far as storminess goes, we’ll have to handle those as they come.  The overall pattern screams towards the idea of an active Ohio Valley to interior Northeast storm track as we move forward (continuing deeper into mid and late winter, as well).  That doesn’t mean one or two storms won’t bypass our local region to the south, due to strong, cold high pressure north, but the mean storm track should put areas through the Ohio Valley in the “sweet spot” from a snow perspective throughout the majority of January, and the rest of winter, for that matter.  Depending on the position and strength of the Greenland Block will have a lot to say about things.  Needless to say, storms cutting NW into the central Lakes should be few and far between after the New Year.  Speaking of storms, we have to continue to keep an eye on the second half of next week.  At the time of this discussion, the threat is still beyond the 7-day period, but circle late next week and weekend for the potential of wintry “mischief.”

No Comments 10-day, AO, Arctic Cold, EPO, Forecast Discussion, Forecast Models, NAO, snow, Unseasonably Cool Weather, WPO