Although it took a little while to get here (just ask Minnesota and Colorado…) it appears that the temperatures have finally started to rise and the last of winter should be over for much of the lower-48.  It’s been quite an interesting weather year thus far compared to recent historic seasons.  Severe Weather is down, Flooding (or drought recovery) is up, moisture is abundant in the the Midwest and South, while precipitation is at a premium out west.  More below:

Severe Convective Storm (SCS) 2013:

There’s no denying that those within the insurance and energy industry have been on edge during the spring following the 2011 and 2012 SCS seasons.  But due to a slight shift in the dominant jet stream pattern (covered HERE by Paul Douglas) has resulted in cooler temps overall which has supported some late season snowfall in NE, KS, MN, and WI.

A secondary result of the jet stream position has been suppressed SCS activity.  Spring activity is usually driven by strong temperature variation between the steamy south and the still-cold northern states.  The migrating jet fuels low pressure systems that kick off supercells and tornadic activity.  But 2013′s setup has resulted in little activity.  In fact, the US is BELOW the recent 7-year average, and by a good chunk!

The combination of cooler wet weather has provided much-needed improvement over much of the Mississippi Valley and Midwestern crop-states prior to the planting season.  However the jet has all but cut off precipitation to much of the Southwest and western states.

Parts of the Dakotas, Nebraska, KS, and Oklahoma should see improvement as temperatures rise and more convective precipitation is produced in the coming weeks.  But there is major concern with regards to the wildfire season for much of the Southwest and California.  The data actually indicates that we are experiencing LOWER activity to-date, but the potential onset of a drought could change that in little time.  The Springs Fire burned through 24,000 acres of the Santa Monica mountains before being contained this week.  NASA has a nice image of the before and after burn scar.

US Precip Anomaly Map

Vendors Launch New Models

If you follow the reinsurance and cat risk management world at all, then you surely caught wind of both AIR and RMS announcing the launch of their newest modeling platforms:  AIR’s Touchstone, and RMS(one).  Both models have enhanced functionality that utilizes decreased analysis time, open framework options for building and using in-house models, enhanced results interaction via mapping and reporting, and cloud data hosting and operations.

These models are standard tools in the reinsurance (and increasingly the primary insurance) world, so any changes/adjustments are always sure to catch the ear of a large audience.  AIR is currently testing their application with a handful of users, and will launch the full implementation in Q3 of 2013.  RMS plans to initiate RMS(one) in Spring of 2014.

You can find lots of information on the respective launches via their twitter feeds:

https://twitter.com/RMS_News

https://twitter.com/AIRWorldwide

In a few weeks we should receive word on the updated North Atlantic Hurricane seasonal forecasts.  Early indications points to another active season.  We will keep you posted.

Zack Schmiesing

The Storm Prediction Center has issued a MODERATE Convective Outlook today over TX, OK, KS and MO today with predictors indicating the follwing:

- 15% chance of tornado activity

- 10% chance of EF-2 up to EF-5 activity

- 30% chance of damaging winds extending over most of MO

- 15% chance of damaging winds extending into northern IL

- 45% chance of severe hail over TX, OK, and KS

- 30% chance of severe hail extending into northern MO

- 10% over OK and KS of 2″+ hail

http://www.spc.noaa.gov/products/outlook/day1otlk.html

Dewpoints > 60F continue to push into Oklahoma this morning, and notable heating over the last few hours is occurring in the region, fueling activity later today as temps continue to rise.  The most recent analysis shows surface-based CAPE values in excess of 3000kJ over parts of Oklahoma.    The jet stream is situated to the Northwest of the region which should support building of super cells.

Effective Shear values are slightly lower than necessary, but are forecasted to potentially increase this afternoon and evening, which would support the storm structure.

We will continue to monitor this system today and tonight

-Zack Schmiesing

email me

The SPC and weather watchers across the Southeast are currently tracking a system that has produced damaging tornadoes in MS, and most recently in Alabama.  The image below comes from the line of storms near Kemper County, MS.

Tornado Watch #98 for Southern AL shows the following probabilities:

Tornadoes

Wind

Hail

Combined Severe Hail/Wind

Courtesy of ABC 33/40

This evening, chances for T-storm activity increase to 70% for parts of northern GA, eastern N. Carolina, western TN, and northern S. Carolina.

http://www.spc.noaa.gov/products/exper/enhtstm/imgs/enh_0000.gif

We will continue to monitor this system for additional information.  Please take appropriate precautions if you are in the immediate area that will be affected this afternoon/ this evening.

Zack

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SCS season under way

The first SCS outbreak of 2013 arrived this week, with 738 Damaging Wind and 30 tornado reports (preliminary) January 29 – 30, stretching across the Ohio and Mississippi Valley into the Southeast and Mid-Atlantic states.  There has been 1 reported fatality, a man caught in an overturned mobile home, which brings a stretch of 220 days without a tornado-related fatality to an end.   The fatality occurred due to the most severe tornado reported that day; a potential EF-3 that traversed I-75 and tossed cars about near exit 306 at Adairsville, GA (Bartow County).

Image Credit: NOAA

Image Credit: AP

Lessons from Sandy

Yahoo!News posted an article today 1/28 on the “10 Lessons From Super Storm Sandy”;

1. Beware Sea Level Rise

2. Skepticism of storm barriers

3. Discuss retreat

4. Consider ways to make retreat possible

5. Re-envision the city

6. Think natural

7. Reconsider costs

8. Don’t fight the last war

9. Keep uncertainty in mind

10. Disasters bring equity issues

You can learn the ideas behind these lessons at YahooNews.

The National Center for Atmospheric Research in Boulder has produced some interesting visualizations utilizing high resolution reanalysis results from the AWR-WRF forecast model.  The short videos provide a look inside the upper level conditions during this unique event, and points to various aspects as to why the storm was classified as “post tropical” prior to landfall.

Zack Schmiesing

zachary.schmiesing@towerswatson.com

The 2012 Atlantic Hurricane Season closed out with 19 named storms, 10 hurricanes, and only 1 major hurricane.  These totals far exceeded the 50-year climatology of 10/6/2, save for major hurricanes.    This marks the 3rd straight year of 19 named storms in the North Atlantic.

Source: NHC

The season got off to an early (but not unseen) start with two tropical storms, Alberto and Beryl, spinning up prior to the unofficial June 1 start date.  Beryl made landfall in Jacksonville.  Debbie marked the earliest formation of a 4th seasonal storm on record, being named on June 23.

August resulted in 8 named storms, the most noteworthy being Isaac, a weak category-1 system that strengthened just prior to landfall at the mouth of the Mississippi River on August 28th.  The system called for the closing of recently constructed Army Corp storm surge gates in the Greater New Orleans area to defend against the 11-foot surge associated with Isaac.  Areas south of these newly updated gates and levies were inundated with flood waters as high as 12 feet.  Isaac proved difficult in its early forecast, at one time indicating a landfall near Tampa as a cat-2, resulting in the postponement of the Republican National Convention.

Source: NYDailyNews.com

Isaac would also serve notice as to the strength of the Euro EMCWF forecast model, which was the first to predict a more northern track away form Midwestern FL and more towards the Mississippi Delta  (though it did struggle with the strength of the storm over time for Isaac).  The model would later nail the eastern seaboard landfall of Sandy.

The only Major Hurricane (cat-3 or greater) of 2012 was fish-storm Michael, which reached cat-3 status for only a short period on September 6th.

The only other US landfalling storm was Sandy on the 29th.  Sandy traversed Jamaica, Cuba, and much of the Caribbean before making eventual landfall near Atlantic City.  Technically, Sandy was no longer a hurricane at landfall, as the NHC re-classified the storm post-tropical just one hour prior to landfall.  The determination was made that Sandy was no longer being fueled mainly by the warm gulf stream, and had started to pull baroclinic energy from an approaching low that was merging with the surface low associated with Sandy.

The storm would go down as one for the record books, including:

1. lowest pressure recorded north of Hatteras

2. 2nd largest wind field, with Tropical-storm force winds extending over 900 miles from the central low

3. the highest (and 4th highest) recorded water heights at the Battery measuring gauge in Manhattan

Sandy would ultimately end up causing and estimated $20B in insured losses, and it will be quite some time before we know for certain what the final tally is.

The lower-category winds coupled with heavy surge damage reiterated the coastal threats of exposure along the water and in low-lying areas, and will be an ongoing discussion when it comes to rates, windpools, the NFIP, etc.

As of Dec 20, the North Atlantic Accumulated Cyclone Energy (as produced by Dr. Ryan Maue) totaled 126.2.  The normal annual value is 104.  The largest contributors were Hurricane Leslie (15.38) and Sandy (14.26).  As a comparison, Ike had an ACE value of 39.19, and Ivan had the largest storm value of 70.38.  ACE is compiled over the lifetime of the storm, so weaker long lasting storms often will have moderate ACE values (as in the case of Leslie this year).

Source: Dr. Ryan Maue

The seasonal forecast groups were mostly incorrect, with Klotzbach & Grey April forecast calling for 8 named storms, 4 hurricanes, and 1 major.  TSR predicted 13 named storms, 6 hurricanes, and 3 major hurricanes.

-ZJS